Arc'teryx Aperture Chalk Bag (Black, Small) APERTURE CHALK BAG - Twist closure chalkbagthe bag opens and closes with a twisting motion that seals chalk inside and shrinks the volume for easy transport. ALPINISM & CLIMBING - Climbing equipment designed for efficient movement and protection in alpine environments SYNTHETIC FIBRE - Engineered materials that offer enhanced properties or performance. Reinforced rim keeps bag open and chalk easily accessible Waist & Belt Configuration