How old of a unit are you looking at ? The Giant Pro life looks identical to the yamaha PW ST model. Here is the Yamaha lineup usually you can tell by looking at them and compare the specs from Giant. Yamaha only supplies the stock motors for Giant and then Giant uses their own software to generally ruin the great characteristics of an awesome motor.
SyncDrive Technology provides pedaling assistance that’s synchronized with human input. It produces smooth pedaling power with a natural feel that is sonically tuned for quiet performance.