This YTX7A-BS is a sealed lead-acid SLA absorbed glass mat AGM rechargeable battery..YTX7A-BS Replacement Battery for Zipp YTX7A-BS - 2PK AGM and GEL batteries are lead-acid and of the same battery chemistry.
1-1/2" Flanged Ball Check Valve, Material of Construction: PVC It unseats to permit flow in one direction but seals against seat to prevent backflow.All sizes rated for full vacuum service. Ball is the only moving part.