15mm tubing with 1/4 extension holes on both ends for splicing with 1/4 to 1/4 screws The 1/4 to 1/4 screws can be spliced to different lengths and can be mounted to extend the corresponding device Use scenario: Used to connection 15mm , or other 1/4 equipment 1/4 adapters, front and back, left and right upper 5 side 1/4 screw holes for expansion of the corresponding accessories Small size, quick installation, easy to carry