[BSTT] Teflon ring assembly tool S50 S54 S62

This tool for installing Teflon rings on the VANOS pistons of BMW M3 and M5 VANOS units with S50, S54, and S62 engines simplifies and improves the otherwise very fiddly and difficult installation of the Teflon ring.

Anyone who has ever done this job without our tool will appreciate it!
In particular, pressing the overstretched ring back into the piston groove is practically impossible without it.
The Teflon rings can thus be installed quickly and easily without damage from overstretching or shearing.