Adjustable height(60mm) support bracket with two rubber washers to protect the finish off of your lens from wearing. The diameter range of the lens works from 50mm to 140mm. The Y shaped long lens support screws onto the 15mm rod clamp to the long telephone lens while shooting. Perfect for long lens and compatible with standard 15mm rod system, help to create a more stable, vibration free platform for shooting. Standard 60mm center spacing fits standard pieces of equipment.There are thumb screw and wing nut on both of the holes, you can tighten this on both rails. There are 1/4 and 3/8 thread holes placements which are versatile. Mount a Monitor or teleprompter on your cinema rig when it's on a tripod/slider. Made of black anodized aluminum,lightweight and durability.