Sierra Designs Flex Capacitor Rain Cover Grey. With elastic on the edges this rain cover fits 25-40 40-60 and 60-75L Flex Capacitor packs. Specifications for Sierra Designs Flex Capacitor Rain Covers: Manufacturer: Sierra Designs Pack Application: Backpacking Color: Grey Fabric/Material: 100percent Polyester Water Resistance Level: Waterproof Features of Sierra Designs Flex Capacitor Rain Cover Features: Fits all sizes of Flex Capacitor backpacks Elastic for snug fit Taped seams for waterproofing 1500 MM waterproof rating Package Contents: Sierra Designs Flex Capacitor Rain Cover Sierra Designs 85711720GY: Flex Capacitor Rain Cover Grey