This is a replacement Air Valve for the CA100 and/or CA125 LP and Natural Gas Mixers
 
4 Options are available:
Standard Silicone (AV1-14-4 IMPCO Equivalent)
Lean Flow Silicone (AV1-14-2 IMPCO Equivalent)
Rich Flow Silicone (AV1-14-4R IMPCO Equivalent)
Feedback Silicone (AV1-1447-2 IMPCO Equivalent)