The parts that extend the rail system beyond sawing. Router adapters put a router on the rail for straight grooves and long housings. Rail connectors join two rails into one, and getting them properly aligned is what stops a long cut developing a kink at the join. The LR 32 hole system is here too: a drilled rail and guide plate that put shelf-support holes on a repeating 32 mm pitch, which is the difference between a cabinet whose shelves sit level and one whose don't. Clamps hold a rail where the grip strips alone won't, and angle units set the rail to something other than square.
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