evo.com | Arc'teryx Long Underwear Tops > The Arc'teryx Rho Zip Neck Top uses Polartec Power Stretch fleece for body-hugging warmth and superior moisture management during high-output activities. Deep zip ventilation and flatlock seams deliver comfort and temperature control in this technical base layer built for big missions. Zippered Sleeve Pocket Fitted Arc'teryx's trimmer fit is patterned to stay close to the body through the chest, waist, hip, and thigh. Its low profile eliminates bulk, moves with the body, and fits comfortably under outer layers. Flatlock Seam Construction Improves next-to-skin comfort. Rho Thermally efficient base layer with excellent moisture management properties. Has stretch comfort. Torrent(TM) 190 with Polygiene(R) 84% Polyester / 16% Elastane | Women's Arc'teryx Rho Zip Neck Top 2026 - X-Small Blue | Elastane/Polyester