Black Diamond Coefficient LT Thermal Top - Men's Hybrid Insulated Base Layer

Cold-weather climbing and ski touring demand a base layer that insulates without overheating, wicks sweat on the go, and moves with every reach. The Black Diamond Coefficient LT Thermal Top solves this by pairing a warm, breathable Polartec® Power Grid™ body with a lightweight Primaloft® Evolve insulated front panel—so you stay warm where it counts and ventilated where you need it.

Who is it for

Built for active men who climb, tour, hike, or trail run in cool to cold conditions. It’s ideal as a standalone mid-layer on crisp days or as a high-performance base under a shell when temperatures drop.

Main features

• Hybrid construction: insulated front panel with Primaloft® Evolve 40g for core warmth; breathable Polartec® Power Grid™ back and sleeves for moisture management.
• Polartec® Power Grid™ fabric (90% nylon, 10% elastane, 125gsm) offers four-way stretch, quick-drying performance, and high breathability.
• Slim, active fit with under-helmet compatible high collar and full-length front zipper for easy venting.
• Integrated thumb loops keep sleeves in place and add hand warmth.
• One zippered chest pocket secures small essentials.
• Bluesign® approved primary fabric for sustainability.

Specifications

• Primary fabric: Polartec® Power Grid™ (90% nylon, 10% elastane, 125gsm)
• Insulation: Primaloft® Evolve 40g (100% polyester)
• Insulation type: Synthetic
• Fit: Slim / Active
• Gender: Men's
• Weight (size M): 215 g
• Pockets: 1 zippered chest pocket
• Closure: Full-length front zipper
• Hood compatibility: Under-helmet compatible high collar
• Sleeve features: Integrated thumb loops
• Moisture management: Wicking and quick-drying
• Stretch: Four-way stretch
• Breathability: High
• Construction: Hybrid (insulated front, breathable back/sleeves)
• Intended use: Climbing, ski touring, hiking, trail running, layering
• Temperature rating: Lightweight mid-layer for cool to cold conditions
• Sustainability: Bluesign® approved primary fabric
• Collar type: High collar

Tips

Layer it under a shell for ski touring or wear it alone during high-output climbs. The thumb loops help seal in warmth when you need extra coverage.