This is a Stock part for:

Losi 1/8 LST RTR-LOSB0010
Losi 1/8 Aftershock RTR-LOSB0012
Losi 1/8 LST2 RTR-LOSB0015
Losi 1/8 Muggy RTR-LOSB0018
Losi 1/8 8ight-T Truggy RTR-LOSB0083
Losi 427 Engine .27 Spin-Start-LOSR1002

Includes:

One (1) Backplate
One (1) Drive Gear
One (1) Bushing