The torsion is transmitted by the synthetic inserts, which allow a smooth and non-shocking transmission of motion. The materials of the inserts are:

1. Elastomer NBR, which is proof against oils, lubricants, gasoline, and petroleum.

2. Polyamide 12 PA12 inserts can be used in environment temperatures from –30οC to +120οC. We can see the technical characteristics of the inserts in table below.  

​

While the torsion is increasing, the inserts are going through compression that results in their temporary deformation. When the torsion stabilizes, the inserts return to their actual form. In this way the inserts act like a spring, and damp any shocks that may occur by the motors, but also help to the reduction of noise.