Estes EST2251
Engine Plugs for 1/2a6 a 8 B4 B6 C6 or E12 Model Rocket Engines
Included are 20 each of the yellow plugs for 1/2A6, A8 and B4 standard engines and magenta plugs for B6 and C6 standard engines.
WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov