The motor can is smaller in diameter. The Fins just makes it look bigger then it really is.
here's a comparison pic. The middle motor is a 8s Feigao.
6 KiloWatt A123 Racer
GTP-Pletty Big Maxximum+RX8. GTP-C50-6L Hacker+RX8. CRT.5-Pro4+ZTW esc.
24s2p EVG SX 49.6mph Ebike.
18s4p Raptor 60mph Ebike. 11.5KW