The Bösendorfer Model 290 Imperial, or Imperial Bösendorfer (also colloquially known as the 290) is the largest model and flagship piano manufactured by Bösendorfer, at around 290 cm (9 ft 6 in) long, 176 cm (5 ft 9 in) wide, and weighing 552 kg (1,217 lb). It has an eight-octave range from C0 to C8. For 90 years it was the only concert grand piano in the world with 97 keys, until it was joined in 1990 by the instruments of Stuart & Sons of Australia. Music critic Melinda Bargreen has described the Imperial as the ne plus ultra of pianos, while pianist Garrick Ohlsson dubbed it the "Rolls-Royce of pianos".