The RIGGER ENGINEERING liner wiper plug landing collar is ONLY used with the latch-in liner wiper plug. IT IS NOT necessary if running a standard liner wiper plug. The collar is located at or near the bottom of the liner string just above the float collar or float shoe. It contains a latch-in mechanism to capture and hold the latch-in wiper plug and drill pipe dart combination, thus ensuring that they will not move during subsequent pumping operations. A secondary advantage to using this type of wiper system is that the landing collar acts as a back-up to the float shoe. When the plug seats in the latch-in mechanism located in the collar, it seals off the bottom of the liner, preventing cement from migrating back up the liner. All components of the landing collar and plugs are made of drillable materials. See latch-in liner wiper plug for more information.