A pair valve system is located on the top of the engine cylinder head, functions as a 1 way valve that pulls fresh air from your intake manifold and then pumps it into your exhaust ports on your cylinder head.
Usually after exhaust and further engine modifications, the tubes, pump, and wires included in the factory pair valve smog system are blocked off. To eliminate unwanted air leaks, using a Block-Off Plate is an easy plug and play method which looks nice and clean.
Yamaha T135 Jupiter MX/Crypton X/Spark/Exciter/Sniper 135
Yamaha Y15ZR/Jupiter MX King/Spark/Exciter/Sniper MXi/ T150
Suzuki Raider 150r/Satria FU150/FX125/FXR150