ERT, GRS series
The ERT series, and the GRS series are manufactured by Bellodi Tibi, and are ER collets. In order for the user to insert the unit, the collet must be inserted into the nut at an oblique angle and rotate it up to link the eccentric ring with the collet groove. Then the user must screw the nut with the collect-chuck. The user then inserts the tool inside at the collect and to screw and to block the nut with a particular wrench.