The ProBoom Ultima Gen2 Table Edge ULP-CLAMP-13 Clamp Assembly is for use with Ultima Gen2 ULP Mic Arms. The base features a quick-lock safety feature to securely lock the arm in place under use, and allows the arm to be easily removed, if needed. A special multi-angle adjustment limiting ring allows for choice of ranges of rotation. You install based on what works best for your needs and safety. No longer do you have to worry about arms going too far back!