Altitude Zip

Fabric Guide Size Guide

Men's Size Chart

Click here to learn more about our different fits and how to choose the size that's right for you.

We strive to make all our products true to size. The sizing chart below is not garment specific, but hopefully, it will give you some guidance when choosing your size. In instances where you’re perhaps in between two sizes try choosing the smaller size.

For further assistance with sizing, contact us here.

Men's General Size Chart

		XS	S	M	L	XL	XXL
Waist	Inch	27	28-30	32-34	36-38	40-42	44-46+
	cm	68 - 70	71-76	81-86	91-96	101-108	111-116+
Chest	Inch	32-34	34-36	38-40	42-44	46-48	50+
	cm	81.5 - 86	86-91	96-101	106-111	116-121	127+

Tracksuit Pants

Outside Leg measurement (including waist band).

Model height 6'2 , wearing a size medium.

		S	M	L	XL	XXL
Inside Leg	inch	29	30	30.5	31	31.5
	cm	74.5	76	77	78.5	80
Outside Leg	inch	41	41.5	42	42.5	43
	cm	105	106	107.5	109	110

Merino-Compression Leggings

Model height 6'3 , wearing a size large.

		XS	S	M	L	XL	XXL
Inside Leg	inch	25.4	26.4	27.4	28.3	29.3	30.3
	cm	64.5	67	69.5	72	74.5	77

Altitude Tights - Ready for Adventure

Model is 6'2" and wears size medium.

		XS	S	M	L	XL	XXL
Waist	inch	25.0	26.9	28.8	30.7	32.6	34.5
	cm	63.6	68.4	73.2	78.0	82.8	87.6
Hip	inch	31.6	33.4	35.1	37.0	38.7	40.5
	cm	80.4	84.8	89.4	94.0	98.4	103.0
Lower Hip	inch	20.5	21.6	22.8	24.0	25.1	26.3
	cm	52.0	54.8	57.8	61.0	63.8	66.9

$120.00

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DETAILS
SIZE & FIT
BEST FOR
FABRIC - ALTITUDE

DETAILS

Our Altitude range is designed to fit close to your body for maximum performance, so it’s tight but still soft, with plenty of give for extra comfort. The Men’s Altitude Zip Base Layer thermal takes natural temperature regulation to a whole new level. It is the perfect ‘go to’ thermal layer for just about any adventure, especially if you’re expecting to hit a range of temperatures. Zip down when it’s mild, zip up and thumb loops on when the temperature drops. The high collar also offers an extra level of warmth beyond the Men's Altitude Crew Neck Base Layer version of this top.

Flatlock stitching, raglan sleeves and tag free to eliminate chafe and maximize comfort. The drop back hem and extra body length is designed for tucking into your outer layers. Thumb loops keep your hands warm and stop your sleeves riding up when layering.

This Base Layer Thermal top is the perfect combination of performance, warmth and comfort.

(For a more relaxed fit try our Ultra Zip.)

Ultra Trail Australia mandatory gear approved thermals.

SIZE & FIT

Designed to be worn as a body tight ‘contact fit’ layer.

Drop back hem and extra length in body.

Thumb loops.

Zip Neck.

True to size.

Model wears size medium in Moroccan blue and green.
Model wears size small in rust.
Model specs - height 181cm, chest 103cm, waist 81cm.

Model wears small in Charcoal marle and black.
Model specs - height 173, chest 99cm, waist 76cm.

Model is 6'2" and wears size large in Dark blue marle.
Model specs - height 173, chest 99cm, waist 76cm.

Size Guide. Contact Fit.

BEST FOR

Snow Sports

Cycling

Running

FABRIC - ALTITUDE

170gsm lightweight

96% superfine Australian Merino

4% Elastane - for an easy all-way stretch.

A MicroMerino® Fabric.

BENEFITS OF MERINO

LIGHTWEIGHT

THERMO REGULATING

SUPER SOFT & COMFORTABLE

BREATHABLE

MOISTURE WICKING

ODOUR RESISTANT

NATURAL

ETHICALLY MADE

Can’t fault it

I find myself virtually living in it full time.

IO

It's the best base layer I have, I've got several kinds but it's my favorite, I've bought two of them 10 years ago in Quebec. Unable to find any more, I made the purchase in Australia and I am still satisfied with the 2022 version.

Great product works well for sea kayaking

So comfortable

I have been wearing IoMerino for probably 15 years now, even going way when it IO BIO. The quality is top notch, and softer and better then the other top competitors. Unfortunately there isn't a Canadian distributor anymore, but that didn't stop me from still purchasing online and shipping here to Vancouver, Sizing is true .with the duty and taxes its a little more, but well worth it my opinion. The Altitude Zip is my favorite, it hugs the body so well, and regulates the heat, and colors are vibrant. During my winter rides when its down to 5c I wear the altitude, pinnacle Zip, and altitude neck tub with a high Vis wind stopping and its perfect. Overall I love the product line, and have many different pieces! The customer support is fantastic as well!

Altitude Zip - Recommendable

This is my second Altitude Zip. What I like: the soft feel, the fit, the high neck, a choice of colours, the quick delivery. It really has a remarkably soft feel, and I enjoy putting it one each time I wear it. I use it in combination with a roll neck jumper in cooler weather, and really appreciate the way the higher-than-average neck keeps me warm, and keeps the coarser wool of the jumper off my neck. I found it 'true to size', ie the 'Large' size fitted me as I expected. It was good to get some colour options, rather than black-or-nothing. I received the item a day or two after I placed the order (and the website was well organised). I can live without the thumb holes, but others will appreciate them, and they don't get in my way. A classy product, and recommendable!

Great top, great service.

Excellent quality and great fit. I really appreciate a company doing an XS size. I had a problem with my first purchase and IO were just brilliant with their customer service. Could not be faulted. I am a fan!

1 2 3

Instagram

Awesome

One of my specific reasons for buying the polo, apart from wearing it casually, I wear it under my yellow protective clothing as a volunteer firefighter. It is extremely comfortable in very hot conditions as it does not stick to your skin when sweating heavily and with the wicking ability helps with managing my body heat. Being wool it also gives that second level of protection against burn injuries.

D.L.

03/25/2023

Universal Polo

foot huggers

The socks are soft, comfortable and fit like a glove, a perfect sock to wear with boots.

D.L.

03/25/2023

Hiking Socks

Amazing!

I have stopped wearing leggings under my skirts for awhile now because of all the synthetic fibers and I decided to get these after a very long search to find the best. After about 1.5 months of searching and reading reviews I decided to get these. I followed the size guide and I found a perfect fit, I never want to take them off. Now I wear long, mostly ankle length skirts and I run in them so I sweat and I sweat a lot but these are amazing. I also have very stretched out skin from having children and these really hold things tight so my skin doesn't hurt when I run or itch. So pleased! I'm super excited to get a second pair but I need to save a bit for them. They also keep their shape after a couple days. I'm so thankful!

Customer

03/23/2023

Pace Compression Leggings - Original

Comfy undies

Fantastic undies for hiking and love the hot pink

Teresa Ukrainetz

03/22/2023

Altitude Brief - Ready For Adventure

Excellent - Love wearing the yoga pants

Great fit, fabric is light and warm
Very comfortable for travelling on long haul flights
Nice to relax around the home in too

Donna

03/21/2023

Yoga Pants

Great trackies

These track pants are a delight to wear. They are light comfortable and easy to wear during any activity. They also wash well. Also smart enough to wear while just out and about.

BRYAN CULLUM

03/21/2023

Stride Tracksuit Pants

Perfect for travel

These yoga pants were perfect for my recent trip to the UK. Comfortable all the way during the long flight and perfect for the cold weather there on arrival. I wore them the whole time I was away and they didn’t crease, lose shape or go baggy in the knees! Am about to buy another pair…

Jillian

03/21/2023

Yoga Pants

Comfort & Style

Beautiful fit. Very comfortable. Bought the set and pleased I did.

Deirdre

03/20/2023

Freedom Sweatpant

Perfection

True to size. Ultra comfortable. Perfect colour match to pants. Super pleased.

Deirdre

03/20/2023

Freedom Sweatshirt

truly excellent underwear

comfy, wicking, long-wearing, dry fast, look great - what else do you need?

CKA

03/17/2023

Ultra Trunks

Great fit, feels good will definitely buy another

Janis

03/17/2023

Universal Tee

the best trunks on the market

being an avid supporter of the merino industry and io merino product i purchased 3 pairs of the mens trunks about 12 months ago- it was not long before i dreaded wearing the cotton brands i was wearing prior to that. I then purchased enough IO mens trunks to ensure i had 100% comfort 100% of the time.

martin moses

03/16/2023

Ultra Trunks

Fabulous hoodie and amazing service!

I’ve been after a good hoodie for a while and had my eye on this. I bit the bullet on Monday, called up, got great service over the phone and when I got home from work today it had arrived! The hoodie itself is feels so soft, fits great and the quality is amazing. Now considering buying a different color! Thanks IO!

R.D.

02/08/2023

Summit Zip Hoodie

New Running Long Sleeve

Only used a couple of times but it’s great. Comfortable fit keeps me warmer than a t shirt and the thumb holes help keep fingers warmer on frigid hills mornings. Time will tell for durability. Love the colour (mint I think)

colin green

01/23/2023

Ultra Crew Neck

No Show Socks

Most comfy socks I’ve ever worn - love wearing them

Jules D

01/22/2023

No Show Socks

Altitude Zip