Lifts with Cable Reel System are already built with cables. For vertical lifting travel more than 2meter, it’s better to add cable reel system for safety concern and better cable management. The lift must be installed vertically and work with weight load 7KG for camera and projector lift Control Ports IO Dry Contact（Manual box control, connected with four-wire or three-wire switch) DB9 Female Port ⑨Common，⑦ UP, ⑧DOWN, ⑥STOP ⑨&⑦ UP ⑨&⑧ DOWN ⑥&⑨ STOP 4. When set the UP/DOWN limit, ensure the belt is shorter than the column. That’s to make the belt to carry load instead of the column in case of collapse