For capping pipe ends. Convex face allows the cap to withstand greater pressure for testing purposes and minimizes ballooning. For temporary or permanent use. Can be use with any material. Suitable for underground use. Not for use on pressurized plumbing systems. Meets ASTM C-1173, C-1277, C1460, CISPI 310, IAPMO PS 109, PS90, & CSA B602.