This is the Venom-Racing Manifold Seal for .12 engines.

FEATURES: Constructed of silicone, blue in color
Provides tight seal between manifold and round exhaust port of engine

INCLUDES: Two Venom-Racing Manifold Seals for .12 engines

REQUIRES: Installing between manifold and exhaust port

SPECS: Outside Diameter: 15.5mm (0.61in)
Inside Diameter: 12.25mm (0.48in)
Overall Length: 9mm (0.35in)