Load ratings are for all four wheels combined. Rating includes weight of Knaack^® product and its contents. Each caster set includes two rigid and two swivel casters with mounting bolts. Caster sets with brakes have the brake unit located on the swivel casters. Knaack^® casters are recommended for use with Knaack^® products.; ; All casters can be used on models TTW208, TTW209, TTW210, TTW211, TTW219, TTW220, TTW222, TTW214, TTW221, TTW212, TTW213. ;