---
type: "product"
id: "rei-coop-midweight-half-zip-base-layer"
name: "REI Co-op Midweight Half-Zip Base Layer Top"
brand: "REI Co-op"
model: "Midweight Half-Zip Base Layer Top"
department: "Running"
category: "Running base layers & tops"
category_id: "running-base-layers"
subtype: "budget synthetic thermal half-zip"
msrp_usd: 69.95
price_tier: "Budget"
price_checked: "2026-10-26"
fits: ["men"]
warmth: "mid"
wind: "none"
water: "none"
visibility: "none"
temp_range_f: [25, 45]
temp_range_c: [-4, 7]
temp_basis: "estimate"
awards: ["Best budget (Cold-weather running guide)"]
url: "https://agenticrecs.com/products/rei-coop-midweight-half-zip-base-layer/"
json_url: "https://agenticrecs.com/products/rei-coop-midweight-half-zip-base-layer/index.json"
official_url: "https://www.rei.com/product/C08396/rei-co-op-midweight-half-zip-base-layer-top-mens"
last_verified: "2026-10-26"
evidence: "Brand specs; 1 published review summarized; not tested by AgenticRecs"
---

# REI Co-op Midweight Half-Zip Base Layer Top

**Verdict:** The value pick: a soft, fast-drying synthetic half-zip that OutdoorGearLab rates a Best Buy, giving up some warmth compared with wool in exchange for a much lower price.

- **Best for:** Runners on a budget who want one warm, quick-drying half-zip for roughly 25-45°F runs or for layering under a shell.
- **Not for:** Runners who want merino's odor resistance for repeat wears or running-specific extras like reflective trim.
- **Downsides:** Less warm than wool for its weight, per OutdoorGearLab; Reviewer found it harder to layer than some rivals; No odor-control or reflective details listed

## Picks

- Best budget in [Winter running base layers and long-sleeve tops](https://agenticrecs.com/guides/cold-weather-running/base-layers/)

## Key facts

| Field | Value | Basis |
|---|---|---|
| List price (MSRP) | $69.95 (Men's list price on rei.com. OutdoorGearLab's women's Best Buy is a different item (REI Co-op Midweight Base Layer Crew, $65 in that review), not verified here.) | rei.com, checked 2026-10-26 |
| Fits | Men's | Brand |
| Warmth | Midweight | Construction (see scale) |
| Wind | None | Brand |
| Water | None | Brand |
| Visibility | None | Brand |
| Temperature range | 25 to 45°F (-4 to 7°C) | Our estimate from the construction |

## Where to buy

- REI Co-op: https://www.rei.com/product/C08396/rei-co-op-midweight-half-zip-base-layer-top-mens

## Specs

| Spec | Value |
|---|---|
| Materials | 92% recycled polyester, 8% spandex; peached face fabric |
| Fabric weight | 220 g/m² |
| Fit | Semifitted |
| Neck | Half-zip, high neck |
| Thumbholes | Yes |
| Odor control | None stated |
| Style number | C08396 |

## Features

- 220 g/m² midweight stretch synthetic
- Peached fabric for a soft next-to-skin feel
- Half-zip front with high neck coverage
- Thumbholes
- Semifitted cut

## What reviewers say

- Gave the men's REI Co-op Midweight Half-Zip a Best Buy award (listed at $70, 220 g/m²), crediting quick drying, soft stretchy fabric, thumb loops and flatlock seams; marked it down for being less warm than wool and harder to layer. Source: [OutdoorGearLab: Best Base Layer (GearLab men's guide)](https://www.outdoorgearlab.com/topics/clothing-mens/best-base-layer), 2026-04-01.

## How this page was made

- Specs, materials and list price: https://www.rei.com/product/C08396/rei-co-op-midweight-half-zip-base-layer-top-mens, checked 2026-10-26.
- Verdict, best for, not for and downsides: our summary of the 1 published review above.
- Temperature range: our estimate from the construction.
- Hands-on testing: AgenticRecs has not tested this product yet.