info@zen3d.hu
M3 square nut for 1515 profile. It is chamfered to a trapezoidal shape, so it can be inserted into the profile afterwards.
You can even prevent slippage with a printed part:
github.com/MotorDynamicsLab/LDOVoron0/STLs/Slide_In_Nut_Support.stl 20pcs / package