The Metabo HPT – Hitachi 878226 Sequential Trip Mechanism Set is a replacement trigger assembly designed to ensure controlled and safe fastening performance in pneumatic nailers. It works by engaging the nailer only when the nose piece is fully depressed and the trigger is pulled, helping reduce accidental firing and improving job-site safety. This mechanism set installs easily in com... https://www.wholetoolbox.com/metabo-hpt-hitachi-878226-sequential-trip-mechanism-set