Founded in 1971, Delta is the worlds 2nd largest electrical manufacturer and has excellent after sale service and technical support in Australia. Technology has moved in strides over the years, but sometimes at the cost of simplicity and usability. Delta inverters are more old fashioned solid robust and not as technologically fancy. No frills, well made machines without the plastic, wifi and technological gadget options. The casing is die cast Aluminium and no plastic like the rest, and the warranty is a long 10 years. If you want simplicity but quality and reliability, the Delta inverter is an excellent choice.