1) High Quality Ceramic Valve Core 2) Made of Ceramic & Plastic 3) Approved ISO, CE, ROHS 4) Working Pressure: 1. ... valve core, welcome to enquiry.[ Material ]: Ceramic & Plastic[ Using Time]: more 700000 tiems, about 7years.[ Quality ]: Approved ISO9001:2000, CE, RoHS standards ... .7515.251718.520.2521.7523.2524.525.7527 25mm diameter High Quality Ceramic Vlave Core