Vanner - based in USA
Vanner was founded in 1977, producing electronics for use in ambulances, including what was claimed to be the first inverter in an ambulance.
4282 Reynolds Drive
Hilliard, OH 43026
Inverters - A range of modified sinewave inverters with outputs of 300 - 2,600 watts
A range of pure sinewave inverters and inverter/chargers with outputs of 600 - 4,500 watts.
Location of Vanner website - http://www.vanner.com