I have reached 100 hours and need to replace CO2 seal. How do I do this?

The Sentinel head will need to be removed from the centre section to replace the CO2 seal. Note. Always remove the counter-lung before attempting to remove the head to prevent damage. Follow the instructions in the manual/assembly-testing document and watch the CO2 seal replacement demo video.

Note. Always apply a thin film of Silicon grease to the CO2 seal with the finger before prior to reassembling the canister to ensure the CO2 canister aligns with the seal correctly. A thin film of grease is all that is required. Do not over grease.

Further Resources

Assembly & Testing Document

Video Link: CO2 Seal Replacement
Video Link: Head Components Assembly
Video Link: Optocon assembly
Video Link: Optocon disassembly