This is a replacement Losi 5mm and 6mm shim set. These shims are used in the transmission, differentials, and on crankshaft between clutchbell bearing and flywheel nut.
These shims can also be used on the TEN-SCTE to shim the rear ring/pinion gear mesh. Use the 5mm shims behind the pinion gear to push the teeth closer to the ring gear.
This product is expected to become available for purchase on Wednesday, February 22, 2023