2XU Apparel Size Chart Warmth without weight is a must-have for trans-seasonal training conditions, and the Momentum Vest is the ideal running companion for layering in cooler weather. Down-like polyester tunnels through the front give wind protection and insulation, while laser cut bonded dividers ensure ventilation is not compromised. Climate fleece back panels complete this lightweight warmth story. Features: - Lazer cut fleece back panel for ventilated warmth - Down-feel polyester filled channels through front with additional laser cutting for breathability - Polygiene for odour elimination - Lightweight and packable - Fabric: Climate Fleece - 100% Polyester - XFLEX Jersey - 87% Nylon / 13% Spandex - Poly Shell - 100% Polyester - Fill - Poly-Down - 100% Polyester