This is a spring loaded cane holder. The slot on the back fits a standard bed leveling spring. The pin size for the hinge is 3mm. Assemble the 2 parts with pin and then add spring. It is a tight fit. The photo shown is my cane mounted horizontally on the underside of a shelf. Be sure that the 2nd piece can move freely, otherwise any binding may negate the force of the spring.

Sovol

SV04

No

Yes