This is the Arrma O-Ring 7.8x2.2mm, 4pcs, AR716034

Arrma 7.8x2.2mm O-Rings. Package includes four replacement o-rings intended for select Arrma 3S BLX/Mega 4x4 550 models.

Fits:
Arrma Big Rock 3S BLX
Arrma Granite 3S BLX
Arrma Granite 4x4 Mega
Arrma Infraction MEGA
Arrma Infraction V3 3S BLX
Arrma Senton 3S BLX
Arrma Senton Mega
Arrma Typhon 3S BLX
Arrma Typhon 4X4 550
Arrma Vendetta 3S BLX
Arrma Vorteks 3S BLX