This sliding bracket is designed for use on a rectangular shower rail. Suitable for standard shower heads, shower clamps for hand held 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 it in place. Easy to install, easy to use. Suitable for riser rails 18mm wide, 30mm long. Please measure the rail diameter before purchase. Content: 1 shower head holder. Note: As measurements are taken by hand, the sizes shown may vary by 1-3 mm. Please order only if you accept this margin of error. The color of the actual item may vary from the pictures, depending on your computer's display and brightness settings. Thank you for your understanding.