This is a Kossel carraige with implant screw support for belt tension and an adjustable endstop tigger screw. liner rail is MGN12H.
M3x8 x4 for carriage implant screw (optional)
M3x16 x4 for liner rail block mount
M3x16 + M3 flange nut for endstop trigger
M3x20 + M3 flange nut for pivot screw (there is a hole design insert from back is easier but you might have already fix this carriage on liner rail block so insert from the froint side is also ok)
M3x10 + M3 flange nut for endstop mount on 2020 aluminium
M2x16 grub screw for OMRON SS-5GL switch mount
Make a small circle on belt, insert the circle to be belt holder. Pull belt then the belt will be tighted. Use zip tie to tighten the belt.