The all SS Kayfun Lite clones use tiny metric screws (of course). The threads are 1.6mm. The length between the thread is .35
You can use 4mm to 6mm long screws on most devices. -some of the Kayfun clones such as the Rocket, use 1.4mm threading with shorter screws (3mm). The threads per mm is the same at .35. -1.4mm thread devices usually have plated brass coil stands. 1.6mm devices use all SS inside the coil base. Hope this helps.