The key specifications of the Catridge, Pre Filter, For 20/35 are — CFM: 20/35 Polyproplene Media; Dimensions: Ø60x90mm(L). These specifications are based on the standard GEM Equipments design; always verify against your machine's requirement before use. GEM Equipments Pvt. Ltd., established in 1984 and ISO 9001:2015 certified, is one of India's leading manufacturers of compressed air dryers, cooling towers, industrial chillers, and compressed air treatment accessories, based in Coimbatore, Tamil Nadu.