The difference between these models is the space taken up by the retiring cam when they are folded, that can be from 65 mm in the case of type 612.UF, to 86 mm in type 612. Another difference is that in type 612.EX on its flat surface the shoe has a length of 310 mm and in the other models 395 mm. The fall of all the wedges is 33 mm.
The operation of these retiring cams is very silent as they are cushioned with rubber stops in the upper joint.
Gervall Catalog PDF®. Retiring cams type 612.00,612.EX and 612.UF