8 large Steel (not plastic) ball bearings Prelubed raceway
Top plate holing 5 3/4" on center of 7/8" slot
5 heavy Coil springs
Quality exceeds most original installed units
8 Ball bearing Style #153A...$57.40
49 Ball bearing Heavy Duty model Style #153A49...$67.05
Heavy Duty, same size, construction and 5 coil springs as in above #153A 8 Ball Bearing style. But with more ball bearings for smoother rolling, providing greater distribution of weight and will be longer lasting. Manufactured for Abacus swivel chair parts to our exact specifications to provide the very best rocker swivel box you can buy! It doesn't get any better than this or we would offer it.