Intumescent Kit. Codelocks PFKP LAT is an intumescent fire kit to fit on new or existing applications, for all Codelocks mechanical or electronic digital locks which operate a tubular latch. It is suitable for use on both 30 and 60 minute timber fire doors and comes with full installation instructions.. Compatible with all Codelocks digital locks featuring tubular latch, including Codelocks Smart Locks. Can be installed on 30 or 60 minute timber fire doors. Contains shaped pads of intumescent strips. For new and existing installations