The main differences between HD1, HD2 and Solis 2:   Product Detail HD1 Dual Motor 2 stage leg actuator HD2 Dual Motor 3 stage leg actuator Solis 2 Dual Motor 3 stage leg actuator Warranty 7 Years 7 Years 5 Years Height adjustment 700mm – 1200mm 625mm – 1285mm 645mm – 1300mm Lifting capacity less 25mm MFC top 100Kg 120Kg 125kg Frame weight 30Kg 32Kg 35kg Speed 32mm/sec 40mm/sec 38mm/sec Frame width adjustment 1150mm – 1740mm 1150mm – 1740mm 1150 – 1700mm Anti collision (solid surface) Yes Yes Yes – With sensitive anti collision Memory controller as standard Upgrade available at additional cost Upgrade available at additional cost Yes Desktop 25mm MFC Fitted with insert nuts for easy fixing through frame using fixings supplied Fitted with insert nuts for easy fixing through frame using fixings supplied Top fixed through frame with wood screws provided no inserts. (Not pre-drilled)