The key specifications of the Check Valve Seal Kit, For 1" ,Non return Valve are — Seal Kit material: Nitrile; Valve Size: 1". These specifications are based on the standard GEM Equipments design; always verify against your machine's requirement before use. GEM Equipments Pvt. Ltd. is an ISO 9001:2015 certified, India-based manufacturer (since 1984) of compressed air dryers, cooling towers, industrial chillers, and compressed air treatment accessories, headquartered in Coimbatore, Tamil Nadu.