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A bearded man wearing a black 100 percent merino wool full zip sweater shown from the waist up against a solid white background.

100% Merino Wool Sweater - Men's Full Zip Heavyweight

$179.99
Color
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This 100% Merino performance sweater offers robust thermal insulation in a versatile full-zip that is rugged enough for tough trails and frigid peaks yet refined enough for town and lodge downtime. 


Description

This 100% Merino wool full-zip heavyweight men's sweater, from the century-old Merino experts at Minus33 in New Hampshire, is a high-durability mid-layer crafted from 100% Merino in a hearty 380 GSM Ponte De Roma knit. Designed with backpack-friendly yoked shoulders, integrated thumbholes, and secure hand pockets, it offers double-knit warmth and resilience across extreme cold-weather conditions.


Materials

  • Fiber Content: 100% Merino Wool
  • Fabric Weight: 380 GSM Heavyweight
  • Knit Type: Double-layer Ponte De Roma Knit
  • Fiber Fineness: 21 Micron Fibers
  • Sun Protection: UPF 50+
  • Certifications: OEKO-TEX® Standard 100, Woolmark®, Responsible Wool Standard® (RWS)
  • Care Rating: Total Easy Care (Machine Wash & Dry)

Construction & Fit

  • Total Garment Weight: 17.6 oz / 498.9g (Size Large)
  • Fit Type: Regular fit — standard cut with room to breathe without being baggy (runs true to size)
  • Layer Type: Mid Layer, Insulating Layer
  • Neckline: Full Zip Mock Neck
  • Hardware: YKK Semi-Auto Locking Zipper Pull with zipper garage to prevent chafing
  • Shoulders: Yoked shoulders with offset seams for backpack strap comfort
  • Cuffs: Integrated thumbholes for easy layering and added hand warmth
  • Pockets: 2 secure hand pockets
  • Label: Tagless design (no itchy neck tags)

Origin & Ethics

  • Wool Source: 100% Australian Merino Wool
  • Ethical Standards: Responsible Wool Standard (RWS) certified animal welfare and land management

Recommended Uses

  • Ideal Seasons: Spring, Fall, Winter
  • Activities: Everyday Wear, Hiking, Camping, Biking, Running, Fishing, Hunting, Snowsports
  • Temperature Range: 0°F and below (Active) | 0°F to 30°F (Inactive)

Size Guide

Measurements refer to body size, not garment dimensions. All measurements are in inches.

Size Chest Waist Sleeve Length Shirt Length Inseam
XS 33–35" 24–27" 30–31" 25.5–26.5" 25–27"
S 35–38" 28–30" 31–32" 26.5–27.5" 28–30"
M 39–41" 31–33" 32–33" 27.5–28.5" 29–32"
L 42–45" 34–36" 33–34" 28.5–29.5" 32–34"
XL 46–48" 37–40" 34–35" 29.5–30.5" 32–35"
XXL 49–52" 41–44" 35–36" 30.5–31.5" 34–35"
XXXL 52–54" 45–49" 36–37" 31.5–32.5" 34–36"
Care Guide: Turn inside out before washing. Machine wash cold on a gentle cycle with like colors using mild or wool-specific detergent. Tumble dry low heat. Do NOT use fabric softener or bleach. For seasonal storage, place in an airtight container.

About Minus33

Rooted in over a century of New Hampshire woolen heritage, Minus33 designs performance-driven Merino wool apparel built for the elements. Born and tested in the rugged White Mountains, the brand focuses on natural fiber performance, thermal comfort, and durable construction for demanding outdoor pursuits.


Product Story

Wilderness Expedition: Minus33's Wilderness Expedition collection is designed to be lighter weight than classic expedition layers while doubling down on durability without sacrificing warmth. Built with a double-knit Ponte structure, these mid-layers withstand early morning bushwhacks, treestand sits, and prolonged alpine exposure.

Ponte de Roma Knit: Ponte de Roma is a double-knitting technique interlocking two distinct layers of fabric. The resulting tight structure provides superior durability, natural stretch, wrinkle resistance, and a clean drape that transitions effortlessly from the backcountry to the office.


Why No Polyester

Your Wilderness Full Zip is crafted from 100% natural Merino wool and not a synthetic blend. Here's why that matters to your health.

Shipping & Returns Policy

Free Shipping: Shipping is free on all orders.

Return Policy: ShirtCastle Originals: Because each ShirtCastle Original is made to order, we're unable to accept returns or exchanges. Please review product details carefully before ordering.

For partner-brand products, contact us at aaron@shirtcastle.com to request a return.

Damages & Defects: In the rare event of a manufacturing error, we will replace your item for free—you do not need to ship the original back. To report an issue, email aaron@shirtcastle.com within 30 days of delivery and attach a clear photo of the defect. We will reply via email and process your replacement.

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