Under Armour Apparel Size Chart The Speed to Burn Tank's HexDelta fabric adapts its breathability and heat retention to what you're doing, helping you maintain a constant temperature. Mesh panels offer increased ventilation, and flatlock seams prevent chafing. A strappy back and shaped hem make it look great too. Features: - Fitted: Next-to-skin without the squeeze. - HexDelta is intelligent insulation that adapts to your activity level for the right breathability & warmth for what you're doing - Breathable mesh panels are ultra-durable & delivers superior ventilation - Ergonomic flatlock seams prevent chafing - Reflective details for low-light runs - Ergonomic shaped hem for enhanced coverage - Cute, strappy racer back design - 95% Polyester/5% Elastane - Discontinued Style / Color - Only available to ship within the USA