With this new idlers it is possible to continuously adjust the tracks. Vast improvement over stock system. Content: Two outside toothed sleeves, two inside toothed idler arms, 2 allen screws M3x6mm. Includes instructions manual
Be advised, the hatch will not close with the periscope in place and the TBS installed. Mount for TBS will interfere with periscope. However, you can lower the TBS mount about 4mm and all will fit correctly with the apple removed.