GMS Store sells generators between 2.3kW and 500kW suitable for the marine, commercial-mobile, RV and home-standby markets.

GMS is the authorised New Zealand distributor for the Cummins Onan brand of generators sized between 2.5kW and 80kW, and the Nanni brand of generators from 5kW to 500kW.

Various specifications – 50Hz or 60Hz, single-phase or three-phase, negative earth, positive earth, isolated earth return, 12 volt starting or 24 volt starting – are available. Some are available with or without sound-shells.

The vast majority of models are powered by diesel engines, although petrol models are available under 5kW.

GMS Store stocks a range of Cummins Onan generators, and spare parts for many machines. It has access to the Cummins Onan global distribution network to order generators and parts not held in stock.

GMS Store sells Nanni diesel propulsion engines, and it indents Nanni generators to order. It has access to the Nanni distribution network to order generators and parts.

GMS Service is available to install, service or repair Cummins Onan and Nanni generators.