Here's what other sites are saying:
The I/O Bio Merino Long Sleeve Zip is our interpretation of the enduring Zip-T. But since we pride ourselves on versatility in our Inside/Outside-You Decide style. We factored a slightly longer back, next to skin fit, endless zip venting, and thumb loops. So, whether you left them in your cold smoke wake or are dusting off from an untimely yardsale, you ll be feeling AND looking good inside and out. FABRIC: Enigma. 96% I/O Bio Merino. 4% Elastane.WEIGHT: 160 g/m2
- Second Ascent refers to the men's version
Great as a baselayer in deep winter when you're chasing powder or alone when it's spring in the mountains and biking season begins, the I/O Bio Merino Men's Contact 1 LS Zip will keep you in all day comfort and style. With endless zip venting and moisture management properties, the I/O Bio Merino Contact 1 LS Zip for men never lets perspiration become chilling moisture and keeps you dry while you're playing hard. Versatile and lightweight, the I/O Bio Merino Contact 1 LS Zip for men is ready to perform.
- Altrec Outlet refers to the men's version
The 100% merino wool I/O Biocompatibles Men's Contact Half-Zip Long-Sleeve Shirt keeps you cool, dry, and smelling like a rose no matter how long you sit out beneath those radio telescopes listening for communications of the third kind. This extremely versatile base layer takes over as your favorite layering piece for anything from a warm, alpine day hike to a January morning ride through the great white deep. I/O's Enigma knit keeps things light so you can wear the Contact under a mid-layer on chilly days or alone when the sun is out. This performance base layer features friction-reducing raglan sleeves and side panels as well as I/O's signature contrast stitching.
- Backcountry.com refers to the men's version