360rotation, more convenient and quick to move underwater without being obstructed by water pipes. Generic thread, you can this adapter according to the diameter of water pipe and breathing valve. Used to connect the Pressure Relief Valve and Medium Pressure Tube, which can be rotated to facilitate flexible underwater activities. Quick connection and quick unloading, convenient and quick. he threaded interface is universal in the world, Used to connect the Pressure Relief Valve and Medium Pressure Tube. Size: 5.5x2.5cm/2.17x0.98inch Interface size(Inner ring diameter): Pressure Relief Valve interface: 1.55cm/0.61inch Medium Pressure Tube interface: 1cm/0.39inch Weight: 27g Rotation angle: 360 [Conversion: 1cm=0.3937 inch, 1inch=2.54 cm] :Aviation aluminum colour:Black Package Contents: 1 x 360 Swivel Regulator Adapte Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.