LIFTMASTER model 8557 residential opener is a 3/4hp belt drive. It is part of the elite series. This garage door opener has an ac motor on 110vac. A battery backup is not available. The remotes are rolling code on MyQ. The rail is style is Solid T.
The warranty on the garage door opener is Lifetime on the motor and 5 years on the remaining opener parts from LIFTMASTER.
The model 8557 is still available.
LIFTMASTER model 8557 residential opener owners manual and instructions in PDF format at NO CHARGE!
VIEW / DOWNLOAD by clicking HERE
liftmaster_8557_om.pdf
(6.07 MB in English) This requires Acrobat 10 or higher