1.Shape: Octagonal, Oval or lens 2.Type: R,BX,RX 3.Size: R11-105,RX20-215 BX150-303, ... Ring joint gasket RTJ1.shape: Octagonal, Oval or lens2.type: R,BX,RX3.size: R11-105,RX20-215 BX150-303, inch1 ... API Standard and meet our customer's demands. API 6A R Series Ring Joint Gasket