... rubber elbows, fan coil joint, sewage check valve rubber, rubber filter, rubber compensator air flue compensator, flexible hanger, rubber shock pad ... ,used at shock absorber and compensate for displacement.JGD mean single ball (arch),JGD-A dual ball ,JGD-B threaded ... on rubber quality . The product mix within the natural one layer, smooth seamless , labels used vulcanization process, together with the ...