Shark Ion Robot Vacuum Cliff Sensor Set - Infrared Drop Sensors Fits Models RV750N, RV761_N, RV700N, RV720N, RV725N, RV850BRN, RV851WV, RV850C, RV850WV RV 750, 700, 720, 725 761 Models must contain the Letter "N". Includes 6 Infrared Distance Sensors as well as the extra Sensor Shark Ion Robotic Vacuum Cliff Sensor Set. Only compatible if your RV700, RV720, RV725, RV750 Model Number Contains the Letter "N" Fits RV750N, RV700N, RV720N, RV725N, RV761_N RV850BRN, RV851WV, RV850C, RV850WV Models Only