6.Connect the chest-extension frame (19), backrest tube (5) and pulley fixing frame (26) with bolts
(M10x70mm)(12), bolts (M10x75mm)(13), washers (26) and locknuts (23). Fit chest-extension arm
(28), chest-extension adjusting board (33) to chest-extension frame (19) with locknut (24) and
powder metallurgy bushing (74),flat washer(12)(33),dish washer(12)(32),nut canopy(M12)(58).