360 rotation allows for convenient and quick movement underwater without obstruction. Compatible with standard thread sizes; select this adapter based on the diameter of your water pipe and breathing valve. Designed to connect the Pressure Relief Valve and Medium Pressure Tube, with swivel functionality for flexible underwater use. Features quick connection and quick disconnection for ease of use. The threaded interface is universally compatible worldwide. Size: 5.5 x 2.5 cm / 2.17 x 0.98 inch Interface size (Inner ring diameter): Pressure Relief Valve interface: 1.55 cm / 0.61 inch Medium Pressure Tube interface: 1 cm / 0.39 inch Weight: 27g Rotation angle: 360 [Conversion: 1cm = 0.3937 inch, 1 inch = 2.54 cm] Material: Aviation aluminum Color: Black Package Contents: 1 x 360 Swivel Regulator Adapter Note: Light shooting and different displays may cause slight color variations between the item and the image. Measurement error allowed is +/- 1-3 cm.