328. SPECIFICATIONSModel 16*17 18*17 20*18 22*18Overall Length(mm/in) 1045 ㎜ (41.1 in) 1090 ㎜ (42.9 in)Overall Width(mm/in)620 ㎜(24.4 in)670 ㎜(26.4 in)720 ㎜(28.3 in)765 ㎜(30.1 in)Overall Height(mm/in) 895 ㎜ (35.2 in) 915 ㎜ (36 in)Total Weight(kg/lb)17.44 ㎞(38.44 lb)17.56 ㎏(38.7 lb)18.54 ㎏(40.9 lb)18.74 ㎏(41.3 lb)Seat Width(mm/in)420 ㎜(16.5 in)470 ㎜(18.5 in)520 ㎜(20.5 in)560 ㎜(22 in)Seat Depth(mm/in) 430 ㎜ (16.9 in) 470 ㎜ (18.5 in)Seat Height(mm/in) 500 ㎜ (19.7 in) 520 ㎜(20.5 in)535 ㎜(21.1 in)Backrest Height(mm/in) 395 ㎜ (15.6 in)Armrest Height(mm/in) 250 ㎜ (9.8 in)Calf Length(mm/in) 360 ㎜~475 ㎜ (14.2 in~18.7 in) 390 ㎜~500 ㎜(15.4 ~19.7 in)Overall CollapsedLength (mm/in) 810 ㎜ (31.9 in) 770 ㎜(30.3 in)Overall CollapsedWidth (mm/in)340 ㎜(13.4 in)360 ㎜(14.2 in)395 ㎜(15.6 in)415 ㎜(16.3 in)Overall CollapsedHeight (mm/in) 750 ㎜ (29.5 in) 870 ㎜ (34.3 in)Maximum UserWeight (kg/lb) 130 kg (286 lb) 160 kg (352 lb)