

What are the differences?
#154 swivel and rock. A stable 5 spring unit used by many quality chair manufacturers. (An upgrade from
supplied 3 spring units)
#15449 swivel and rock will hold up longer than #154 and take a greater weight usage due to the larger quantity of steel ball bearings. (5 springs)
#3540 custom adjustable rocking action allows the user to custom adjust the rocking action from "soft" to "hard". The 3 springs are a heavy gauge. 2 springs up front and 1 adjustable spring at rear. Heavy duty 49 steel ball bearings. View-how to adjust

1. 8 ball bearing 5 spring Residential duty style #15449 ball bearing 3 spring
2. Residential duty Adjustable rear spring style #3540
3. 49 ball bearing 5 spring Heavy duty style #15449
Installation drawing
Style #154-8 ball bearing...$56.20
Style #15449-49 ball bearings...$62.60
Style #3540-49 ball bearing...$72.60
