Arc'teryx Ion Lightweight Chalk Bag - BlackChalk up without losing your flow. The Ion Lightweight chalk bag from Arc'teryx rides light and is designed for easy access to chalk while youre on the move. The siliconised polyester is extremely light, strong and water resistant. The spiral closure opens wide but also closes tight to prevent spills while travelling. The waistband adjusts for a comfortable fit, and a loop holds your chalk brush. Siliconised 100D dobby weave polyester Pack Attachment