On Running's Zero Singlet is an ultra-lightweight race-day tank designed for high-intensity runs, offering moisture-wicking performance and breathability with reflective detail for low-light visibility. Key attributes: Black | Polyester | Moisture-wicking | Lightweight | Breathable | Athletic racer-back styling | Reflective detail at back | Sleeveless | Perforated pattern | Straight hem | Dimensions & fit: Close fit | True to size | Composition & care: Polyester 90% | Elastane 10% | Machine wash cold; Do not bleach; Do not dry clean; Do not iron; Do not tumble dry; Wash inside out.