Merino Core Lightweight Half-Zip
Merino Core Lightweight Half-Zip

Merino Core Lightweight Half-Zip

  • Big Game : Optifade Open Country
(11 Reviews)

The new Merino Lightweight Half-Zip features premium 17.5-micron merino wool spun around a nylon core, creating a high-performance next-to-skin layer that combines the comfort, warmth, moisture management and natural odor control of merino with the durability and elasticity of nylon. With a high heat-to-weight ratio and excellent breathability, the Merino Lightweight Half-Zip excels as a versatile base layer across a broad range of conditions and activity levels.

Product ID: #10056

Sizing Guide

Jacket & Tops Sizing

Size Chest Sleeve
Small 36 - 38" 33"
Medium 39 - 41" 34"
Medium Tall 39 - 41" 36"
Large 42 - 45" 35"
Large Tall 42 - 45" 37"
X-Large 46 - 49" 36"
X-Large Tall 46 - 49" 38"
2XL 50 - 53" 37"
2XL Tall 50 - 53" 39"
3XL 54 - 57" 38"

Pant Sizing (Inches)

Size Waist Reg Tall
30 30" 31"
31 31" 31"
32 32" 31" 33"
33 33" 32" 34"
34 34" 32" 34"
35 35" 32" 34"
36 36" 33" 34.5"
37 37" 33" 34.5"
38 38" 33" 34.5"
40 40" 33"
42 42" 33"
44 44" 33"

Pant Sizing

Size Waist Reg Tall
Small 28 - 30" 31"
Medium 31 - 33" 31" 33"
Large 34 - 37" 32" 34"
X-Large 38 - 41" 32" 34"
2XL 42 - 45" 32" 34"
3XL 46 - 49" 32" 34"

Equinox & Dakota Pant Sizing

Size Waist Reg Tall
30 31" 31"
32 33" 31" 33"
34 35" 32" 34"
36 37" 32" 34"
38 39" 32" 34"
40 41" 32"
42 43" 32"
44 45" 32"

Glove Sizing

Size Palm Circ Length
Medium 8 - 8.5" 7.5 - 8"
Large 9 - 9.5" 8.5 - 9"
X-Large 9.5 - 10" 9 - 9.5"
2XL 10 - 10.5" 9.5 - 10"

Gaiter Sizing

Size Calf Circ Boot Size
M/L 17.5" US 6-10"
L/XL 18.5" US 10-14"

How to Take
Your Measurements


    Bend your elbow and put your hand on your hip. Measure from the center of the back of your neck, along the shoulder and down the elbow to the wrist bone.


    Take measurement under armpits, around fullest part of chest and shoulder blades.


    Measure around where you normally wear your pants, keeping the tape measure a bit loose or putting one finger between your body and the tape measure.

  • 4. INSEAM

    In a standing position,measure from your crotch to where you want your pants to end, breaking at the top of the shoe in the front and just above the heel in the back.

  • 5. GLOVES

    With hand partially closed, measure over the knuckles, around the hand, excluding the thumb.

Fit Guide

SITKA Gear engineers gear with a specific Fit and intended end use in mind. These functional designs provide the user with authentic garments for the right situation.

Fit Descriptions

We can communicate our Fit descriptions in 3 different ways. Keep in mind that each garment will allow for layering in accordance to the garments place in a system and described Fit

  • P/F
  • S/F
  • E/F

    Designed for minimal layering. Whether an early season piece or already insulated this garment fits to prevent inefficiencies in heat retention caused by dead space.


    Designed to accommodate layering for more versatility from early to late season climates.


    Designed for maximum layering in the worst conditions. Cut roomier to accommodate additional layering underneath.

Back to Shopping
  • GORE™ OPTIFADE™ Concealment Open Country is scientifically optimized for engagement ranges of 50 yards and beyond at ground level in rocky terrain above the timber line.

  • Weight: 5.8 oz. // Size: L

  • Fabric: 85% 120-Gram 17.5 Micron Merino / 15% Nylon Core-Spun Blend.

  • Imported

Product is Performance Fit, designed for minimal layering.

Product Comments

11 Reviews
Write a Comment
Reviewed On 06/28/2021

I don’t find the shirt being too short I have there competitors shirts and I find them being the same length I wish they would make it in a hoodie with the face mask in it the merino is far superior over the synthetic very good product

Jacob Jordan
Reviewed On 12/11/2020

I wore this as a base layer all season this year and loved it overall. The material quality is outstanding and I love the half zip for early season elk and deer. As others have commented however, this piece is just too short. I own many different merino pieces and know how to care for them properly so this wasn't a case of me putting it in the dryer, it is just short. I will continue to wear the one that I have but if Sitka would correct the issue, that would ensure that I buy more in the future.

Karl Marlowe
Reviewed On 11/13/2020

Just picked up this base layer before my October elk hunt, it has quickly become my favorite base layer, and my wife loves it as well. Fits well and like all of my other merino wool products, doesn't stink after the 3rd wearing. Easy care, remarkably soft and comfortable. Like my Sitka soft-shell, this fits as well or better than any of my other performance brands that I use for skiing, cycling and other outdoor pursuits. I'm buying another.

Reviewed On 11/07/2020

This shirt is strong for merino. Quality is great! I’ve worn 2 of them for a few seasons from September to January in the Southwest. Problem is, they are just too short. I love the shirt, but I find myself avoiding it due to length.

John Abernathey
Reviewed On 07/17/2020

I almost love this shirt, but they are about 3" too short. I'm 6ft tall so fairly average. I have owned merino hunting shirts in the past so I am aware of not drying merino due to shrinking, so I hang dry all my merino camo, but this shirt is frustratingly short. Hoping Sitka fixes this asap! I would totally buy some more once they get the length fixed.

Reviewed On 05/21/2020

Very comfortable with a great fit. Less shiny than the synthetic base layers. You would likely do as well with the synthetic Core lightweight shirt for better durability and lower price. I'm not sure if the value is there with the merino shirt but it slightly nicer overall.

Reviewed On 01/19/2020

Light weight merino half zip I can't wait to put to the test throughout archery season. Plan on purchasing a second one soon. Sizing advice: I'm 5'11" 170 lbs, athletic build, wear a medium in almost everything including my black ovis merino T's and half zip, and I'm definitely glad I went with a LARGE in this shirt or I would likely be rocking a belly shirt come hunting season. As a large, it's still not baggy and I'll be able to tuck it in.

OR Elk Hunter
Reviewed On 12/07/2019

Great base layer or shirt for warmer weather. Super soft and VERY comfortable. I accidentally ran this through the dryer and it didn’t shrink! But, I do wish the length was a little longer in the torso. I find myself “tucking” more than I would like. Four and 1/2 stars for this reason.

Mitchell Clifton
Reviewed On 12/10/2018

I paired it with the light merino wool bottoms and was very pleased. Weight to warmth is amazing.

WA State Hunter
Reviewed On 10/12/2018

Great product!! I was skeptical of all the hype about merino wool... but it is all true. These were extremely lightweight, but did a great job with maintaining body temperatures. Used during September early archery elk hunt. Did 6 days strait of hunting/hiking. Temperatures ranged from 30-70 and we hiked anywhere from 10-20 miles daily with about 3k elevation changes. I was never uncomfortable, wore either the ascent shirt, apex hoodie, and sometimes the kelvin light down jacket (no longer being made) with it depending on how the temperatures were looking. Even more impressive to me was that the base layers really did not smell at all. Im sold on it, will highly recommend to everyone. I hope Sitka will continue to produce more merino wool products, such as a t-shirt and more mid layers.

Reviewed On 09/04/2018

I think Sitka is really onto something with the Nylon/Wool combo. The quick drying property of nylon and the odor resistant property of wool work really well together. BUT no thumbholes for a $140 baselayer?

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SITKA Gear - 07.26.2017

The Linguists

Few sounds in nature rival the bugle of a bull elk. Join nine-time World Elk Calling Champion Corey Jacobsen as he explores a hunting legacy with elk calling pioneers Larry D. Jones, Wayne Carlton, Rockie Jacobsen, and Will Primos.