| Origin | Selangor, Perak, Malacca, and FMS Railways | Builder | Kitson, Hunslet, Neilson Reid, R. Stephenson (England/Scotland) |
| FMSR Class | G | Cylinder | 14.5 x 20 inches |
| FMSR Number range | 36-69 | Boiler Pressure | 150 psi |
| KTM Class | n/a | Driving Wheel Diameter | 51 inches |
| KTM Number range | n/a | Water Capacity | |
| Introduced | 1899 | Weight Full | 30 tons |
| Extinct | July 1947 | Tractive Effort |
The G class was the principal main line class in the early days of the FMSR, and lasted in service a total of 50 years.