REI Co-op Midweight Base Layer Half-Zip Top - Women's

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An ideal first layer for playing hard on cold days, the women's REI Co-op Midweight Base Layer half-zip top offers the warmth of long sleeves and easy venting thanks to a front zipper.

  • Features

    • Smooth outer face lets layers slide on easily, while a brushed interior provides warmth
    • High neck coverage with a half-zip front lets you open up for venting when you're working hard
    • Fabric wicks moisture and dries quickly to keep you comfortable
    • 4-way stretch delivers a flexible range of motion
    • Flatseam construction reduces bulk and chafing, and rolled-forward shoulder seams prevent abrasion from pack straps
    • UPF 50+ rating protects against sun rays


    View all REI Co-op Women's Base Layer Tops
  • Technical Specs

    Best Use


    Shirt Type



    92% polyester/8% spandex

    Sun-Protective Fabric


    UPF Rating


    Moisture Wicking


    Quick Drying


    Underwear Weight


    Sleeve Length

    Long Sleeve



  • Size Chart

    Numerical Size000-24-68-1012-14161820-2224-2602468101214161820222426
    Sleeve Length29.53030.53131.532.533.533.534.5303030.530.5313131.531.532.533.533.533.534.534.5

    Sizing Notes

    Measurements are stated in inches unless otherwise indicated. Some women's pants are available in petite and tall sizes. Typically petite sizes fit women 4'11" to 5'3". Regular sizes fit women 5'4" to 5'8". Tall sizes fit women 5'9" to 5'11".

    PETITE: Generally, as compared to regular sizes, petite sizes are 2.5 inches shorter in inseam, 1 inch shorter in body length, 1.25 inches shorter in sleeve length and ¾ inch shorter in total rise.

    TALL: tall sizes are 3 inches longer in inseam, 2 inches longer in body length, 2.5 inches longer in sleeve length and 1.25 inches longer in total rise.

    Capri or cropped pants have an intentionally shorter inseam—reference the technical specs instead of this chart.

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    245 reviews with an average rating of 4.8 out of 5 stars

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