Release cartridge Cartridge UML Pro Sensor MK2, United Moulders for automatic lifejackets with United Moulders (UML) Pro Sensor release system. The set contains the release cartridge. Replacement should be carried out every two years at the latest, or annually in the case of intensive use, and can be carried out by the user. At least one complete maintenance set including cartridge and gas canister should always be carried on board to make deployed lifejackets ready for use again on site!