Summary

Block bar smooth 8 mm, the blocks are designed for a section of iron or aluminum 20 mm thick, there are two so you can have them facing each other, there is also the bar lock with built-in support for the endstop, is designed for a 20x10 mm microswitch like those of the Anet A8, these blocks I used them for a welded iron frame with 20x40 mm profiles and they work perfectly, in the pictures you see that there is also a piece that has the seat for two M4 nuts to be inserted into the profile, the blocks are designed for 16 mm M4 Allen screws.