Material: Nylon; Thread: M4; Female-Male Thread Length: 50mm+6mm; Packing List: 20pcs Standoffs, 20pcs Nuts Application: Our standoff screws are widely used in computers, computer cases, circuit board assembly, electronic fields, etc. The PCB standoffs play a supporting, isolating and fastening role in the use. Advantage: The nylon standoffs are rust-free, durable, stable, and reusable compared with metal standoffs, feature non-conducting, and can fix your boards firmly in place. Instruction: The standoffs are perfectly used to organize the controller board and the sound boards, to keep PCB at a consistent height and prevent it from bending, twisting, and short-circuiting. Note: Please measure the required length of your project, and then select the appropriate standoffs to save your time and effort.