2)trolley on t-rail, 3)fasten t-rail to the opener, Caution – Chamberlain 7220 1/2HP User Manual

2)trolley on t-rail, 3)fasten t-rail to the opener, Caution | Assembly step 2, Assembly step 3, Install the trolley, Fasten the t-rail to the motor unit | Chamberlain 7220 1/2HP User Manual | Page 9 / 40