The LiftMaster CPS-EI commercial garage door operator protector system edge interface from Garage Door Supply Company is for use with LiftMaster Logic commercial door operators with four-wire monitored sensing edges. LiftMaster's CPS-EI will reverse a garage door to the open position if the system detects an obstacle in the path of the door sensing edge. This stand-along reversing system should not be used with other entrapment protection devices. Product Highlights: