38mm 1/8 inch diameter Red Silicone High Temperature O-Rings 5 pack. These O-Rings are designed for high temperature use up to 400 degrees F and survive under the extreme abuse the CNVA puts on the motors internal parts. O-Rings need to visually inspected for any wear or heat damage. rotating them with the Nozzle as the wear as they tolerate the intense heat. All High Performance Motors should use these on the Injector Baffle and Nozzle.