Fire alarm detector base stand off

This design is to mount on the ceiling and a detector base then mounts to it, most commercial addressable and conventional detector bases should fit, as well as some domestic smoke alarms and also some lighting units.it is designed to allow a route in for cables if the base has cable channels that are too tight.unfortunately i could not find any M3.5 nut inserts to buy so i had to design it to use M4 heat set inserts so you cant use standard electrical screws but M4 set screws will still fit in standard base slots.this was tried and tested on a bambu a1 with the standard 0.4 nozzle, standard textured build plate and standard settings i printed it in white sunlu pla+ using the built in settings for esun pla+.