These stainless steel guide rail dogs, hidden beneath the rail, offer superior security and precision. The guide rail dogs prevent saw cutting across other dog holes. Tee-bolt design fits into the rail’s Tee-slot, replacing the need for rail clips. The knurl on the lead taper helps to lock the dog to the rail. Laser-etched 0-75mm scale for wood thickness measurement. Supplied in a pack of 2 with split stop collars to set the wood thickness.