This is a multifunctional spacer , designed to mount a Unifi AP Pro in an Ikea KALLAX shelf. The spacer creates a 3 cm cavity between the shelf and the access point. I used 3 spacers to mount my AP and it is solid!
The height of the spacer is 3 cm. The dimensions of the base are 30x12x4mm. There are 3 holes for 4mm screws.