The G 4-2 R features a single main rotor, a two-seats-in tandem enclosed cockpit, tricycle landing gear and a four-cylinder, air and liquid-cooled, four-stroke, dual-ignition 1000NaN0 Rotax 912S engine in pusher configuration. The 950NaN0 ULPower UL260i powerplant is optional.
The aircraft fuselage is made with a stainless steel tube frame; the cockpit is formed from carbon fibre. Its 8.41NaN1 diameter two-bladed aluminium Averso rotor employs a NACA 8H12 airfoil and has a 1500-hour time between overhauls. For safety the fuel tank incorporates ME Rin anti-explosion technology. A second fuel tank of the same capacity can be optionally added. Baggage capacity is two compartments. The aircraft has an empty weight of 2620NaN0 and a gross weight of 4500NaN0, giving a useful load of 1880NaN0.
Even though the manufacturer is an Austrian company the aircraft is built in Slovenia. The G 4-2 R was noted by Bayerl et al. in 2011 for its unusual new aircraft two-year warranty.