Rho Series: Thermally efficient moisture wicking base layer. LT: Light Weight. Built with highly durable top performance materials but designed with streamlined minimalist set of features to provide very light weight. Trim fitting, the Rho LT remains a lightweight, thermal foundation piece suited to cool temperatures and slower paced activities. Plush interior has rich, warm texture and the elastane content keeps the fabric in constant contact with the body to retain thermal efficiency. Zip neck opens to aid rapid temperature regulation. Features: Moisture-wicking Warm-when-wet Minimal odour retention No-lift gusseted underarms Chest half zip Laminated chest pocket with laminated zip Next-to-skin fit Weight: 240 g / 8.5 oz Activity: All Round Materials: Torrent(TM)-84% polyester 16% elastane. Moisture wicking, breathable, stretchy, jersey knit textile with a soft, brushed surface and a Polygiene(R) finish to manage odour. Polygiene(R)