This sliding bracket is designed to be used on a rectangular shower rail kit. Suitable for standard shower heads, shower clamps for shower heads with standard connector. Fully Adjustable: Simply press the button to adjust the height of the brackets on the rail and release to secure. Easy to install, simple to use. To fit a rail of 18mm width, 30mm length. Dimensions: 11.8 x 4 x 2.3cm. Please measure the diameter of the rail before purchasing. Package Included: 1 x Shower Head Bracket. Please allow 1-3mm error due to manual measurement. Please only place an order if you accept this margin of error. Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thanks for your understanding.