This is a 55 pound direct pull strength magnet with 1/4″ 20 thread, which when used with an articulated arm, allows you to attach the MiniCine Light to any ferrous metal with plenty of support. It is rubber coated so it won’t damage surfaces. It is 2.6″  or 66mm in diameter. I recommend using this with the Articulated Arm we sell, to give you maximum flexibility of getting the light where you want it.