Featuring M6 threaded screws, this four-pack of T-Shape M6 Screw Knobs & Gaskets from Neewer can be used with a variety of photo/video gear for tool-free operation and extra clamping strength. Compatible equipment includes Neewer 480/530/660 LED lights. The knobs feature ergonomic T-shaped handles with a satin texture. They're made of thermoplastic and stainless steel and are scratch-resistant.