Being a runner I was searching for a good quality merino running top to get me through early winter mornings.
Wanted cloth that was a bit thicker than the usual sports tops and this top’s description mentioned this.
Did take more of comments about sizing so ordered a large (I am usually a size 6-8 or XS)
It is perfect! Great fit, beautiful quality fabric, super comfortable, perfect length and most importantly lovely and warm and high neck keeps morning chill at bay.
Will be purchasing another and would definitely recommend but if not wanting skin tight sausage-skin fit - recommend at least two sizes up.

Love the soft feel and cosy fit. Looking forward to wearing it on our 1000 k hike.

I just love this zip top. It is so snug and warm around my neck and the wool is so soft and comfortable. No itching and the zip is neatly tucked away so it doesn't scratch, unlike my previous zippy thermals. Beaufort quality, so keen to get more in different colours. Thanks You 🙏

First I bought 2, then I bought 2 more. I am a runner, and I am always cold in between, so I live in skivvies all winter. I'm replacing them all with these tops- they are warm, snug on the body, super flattering, love the extra length that doesn't let any draughts in from the bottom. Great customer service too, 2 of the tops had some stitching issues and it couldn't have been easier to get them replaced. Will definitely buy more! Im a pretty standard M, and went with that size, and they are perfect.

I live in Lake Tahoe and wear this year round. It is perfect for ski days, hikes or cold days on the lake. I’m 5’10 and 150 lbs. I wear a size large and it is the perfect fit. Long sleeve and torso, I want it in every color.

Neat fit. Appreciate sleeve and body length being a little longer than strictly necessary - longer by 2 cm than my existing ioMerino, much-worn, collared tops.
Kath. (165 cm, 52 kg)

This is my third purchase from IO. I love their high quality, warm, long-lasting tops. I am normally a small but medium fits me best with IO. I wouldn't buy any other brand.The service is absolutely perfect every time too.

First purchase from IO and I'm extremely happy with this top. Since buying online can be tricky with sizes, I chose an L due to IO sizing guide, pictures and customer comments. I would normally wear a size 10 in most tops, and found the L to be perfect. The colours are gorgeous, so nice to see fashion trendy colours in these products. The material is so beautifully soft and light and will make great travel tops as well.

Love this top, purchased as my previous one had thinned after years of use. Light weight and comfortable next to the skin

Purchased XS usually size 8 too fits perfectly no sagging. Looks great nice contoured fit. Feels great made very welll.

I was able to stay warm, layer up and stay comfortable with my 3rd Altitude Zip. Loved the discount

Great product quality, made with attention to detail, light, soft and comfortable. Would be good to be available in red as well. A bit expensive

Toby I spoke to was fantastic
If I order again he will take my order.
Purchased 6 items all good however 1order was for xs but sent medium
Not impressed
Graham Tucker

I ordered the medium size and it’s more like a small size, it’s a lovely colour thought

Excellent warm light washable wool, * very cool style and cut cut Perfect layer, Size 8 perfect fit, I love the look high neck zip and The fitted panels, a great colour which is so hard to find, I brought one last year, And got another just now,

This top is just as pictured. It is so flattering! The material is extremely soft and it's nice enough to wear as a top without covering it up under your other layers.

LOVE IT

Great top. Bought to wear under my ski jacket. Warm and comfortable. I sized up to a medium after reading the reviews and it fits perfectly (all my other iomerino gear is size S).

Awesome quality as always from IO however I would suggest going up 1-2 sizes. I'm usually a medium which was more like a size 8. I exchanged for a size L however an XL would have perhaps allowed me to wear a tshirt underneath. I don't think anyone over a standard size 16 would fit this style (altitude).

My wife who no matter which season is cold the Altitude pullover does the job of keeping her warm all the time.
We finaly found an outer layer that works as described along with a beautiful look, feel and quality light knit finish.

The most striking blue colour. Cozy and thin, perfect as an underlayer or for in-between seasons. With the zip up it covers nicely the neck. It is my second one - I love them! Thank you IO

Smart enough to wear casually out, comfortable for running and riding, does what the bio says. True to colour. I had one previously, lasted years but finally wore out, expect this will last just as long

Love this top - it fits perfectly and is a magnificent colour. Thankyou io

Great top, love it, modern and stylish, light and warm. I had a faulty zip on first order but company very quickly sent me another free of charge and postage. That was great i hadn’t expected that Great service and reputation. Thankyou

Fits well, high quality, very impressed.

Comfortable, soft, not stinky. Exactly what I expected, it’s a skin fit - as described. I’m a size 10 usually and got a size small - it fits like the pics. My only improvement would be if you could put those slots in the arm so you can poke your watch through when running, the sleeves are hard to pull over my watch.

Light, body hugging, gorgeous colours and collar gives that extra neck warmth low cuts lack

This is my second iomerino altitude zip, I absolutely love it and wouldn’t survive winter running without it. Super warm and gets me out on a 3 degree day at 5 am. Wouldn’t be without it ever. Cheers ioMerino keep up the good work 🌟

I bought this top for my son for his cross country/winter running training. He stated it fits well is nice and warm and is extremely comfortable to wear. Highly recommended.

I bought the Altitude Zip in bright rose, as my base layer ahead of some winter trail runs. I’m loving it. Wicks moisture beautifully, washes well, and the colour is gorgeous. Will be buying more.

Love my altitude zip, this is the second purchase. Pretty sure I’ll end up with one in each colour.
Comfortable, warm and light. Best of all no stink!

Awesome top my wife loves it as with all her io merino sports clothes. Very comfortable, no sweat, she loves running in it and also great for general wear in and out of the house