How to Choose Base Layers
REI Co-op Midweight Base Layer Half-Zip Top - Men's
This product is not available. Good news: we have a newer version.
Designed to keep you warm and wick away moisture, the REI midweight half-zip base layer is ideal for high-performance cold-weather outdoor activities.
Shop newer version- Made of a durable yet soft polyester / spandex blend that wicks sweat and dries fast
- Tall neck extends coverage; zipper with chin guard lets you adjust ventilation
- Flatseam construction, raglan sleeves and side gussets are comfortable as you move
- Extended back hem stays tucked in when you lean forward
- UPF 50 sun protection
- Fitted
- REI Co-op brand is certified to The Climate Label; we actively fund efforts to reduce carbon emissions across our business and support climate projects around the world
| Best Use | Multisport |
|---|---|
| Shirt Type | Partial-zip |
| Fabric | Polyester |
| Sun-Protective Fabric | Yes |
| UPF Rating | 50 |
| Moisture Wicking | Yes |
| Quick Drying | Yes |
| Underwear Weight | Midweight |
| Sleeve Length | Long Sleeve |
| Gender | Men's |
| Sustainability | From a Climate Label Certified brand |
REI Co-op Clothing - Men's
| XS | S | M | L | XL | XXL | XXXL | 24 IN Waist | 26 IN Waist | 28 IN Waist | 30 IN Waist | 31 IN Waist | 32 IN Waist | 33 IN Waist | 34 IN Waist | 35 IN Waist | 36 IN Waist | 38 IN Waist | 40 IN Waist | 42 IN Waist | 44 IN Waist | 46 IN Waist | 48 IN Waist | 50 IN Waist | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chest | 35 | 36 - 38 | 39 - 41 | 42 - 45 | 46 - 49 | 50 - 53 | 54 - 57 | |||||||||||||||||
| Sleeve Length | 32 | 32.5 | 33 | 33.5 | 34 | 34.75 | 35.5 | |||||||||||||||||
| Waist | 27.5 | 28 - 30 | 32 - 34 | 36 - 38 | 40 - 42 | 44 - 46 | 48 - 50 | 24 | 26 | 28 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 38 | 40 | 42 | 44 | 46 | 48 | 50 |
| Hip | 33.5 | 34.5 - 36.5 | 37.5 - 39.5 | 41 - 43 | 44 - 46.5 | 47.5 - 50.5 | 51.5 - 54.5 | 32 | 33.5 | 34.5 | 36.5 | 37 | 37.5 | 38.5 | 39.5 | 40.25 | 41 | 43 | 44 | 46.5 | 47.5 | 50.5 | 52.5 | 54.5 |
| Inseam | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 | 32 |
Sizing Notes
Measurements are stated in inches unless otherwise indicated. Size chart values represent body measurements, not garment measurements.
SHORT: Some pants are available in short sizes, which generally means an inseam that is 2.5 inches shorter than regular sizes.
TALL: Some pants, shirts, jackets and parkas are available in tall sizes, which generally means an inseam that is 3 inches longer and a rise that is 1 inch longer, a shirt or jacket body that is 2 inches longer, a parka body that is 2.5 inches longer and sleeves that are 2.5 inches longer than regular sizes.
Capri or cropped pants have an intentionally shorter inseam—reference the technical specs instead of this chart.
Inseam is measured to the floor.
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Location:Chicago, IL
9 years ago
Great Product
Yes , I recommend this product
Very comfortable, being just snug enough to look fitting but loose and stretchy enough to keep you from feeling constrained. The perfect weight and thickness for what I was looking for.
Location:Astoria, OR, United States
8 years ago
Warm on a cold windy day
Yes , I recommend this product
I bought this item in preparation for a hike on the Oregon portion of the PCT and decided to try it on a local hike on the Oregon coast on a cold and windy day. This item kept me warm and was a pretty solid windbreaker also. Doesn't over heat you either. I can't recommend this item enough.
Location:Boise, ID
8 years ago
Pretty good garment
Yes , I recommend this product
This is called a mid-weight shirt. What that means is that you cannot read a book through it like you can with many flimsy under layer tops. It didn't shrink when I washed it. (Yes some of the REI poly fabrics shrink and I don't know why). The fit is reasonable although true-to-size fit seems to be a thing of the past. So all in all it's pretty good
Location:Burbank, CA, United States
9 years ago
Perfect light weight pullover
Yes , I recommend this product
I travel allot on airplanes and needed a light weight pullover, this is perfect. Doesn't wrinkle and fits nicely. Wish it had a small pocket. I'll use this winter as a base layer for skiing.
Location:Cincinnati OH
8 years ago
Used for sking in Utah last month. Toasty.
Yes , I recommend this product
Well made mid weight base layer. Excellent construction. I would recommend highly.