Transport objects weighing up to 300 pounds with this medium-duty swivel caster. Built for most industrial applications, this caster has a double ball raceway with an adjustable lock, a zinc frame, and has a four-inch diameter phenolic wheel with a 1 1/2-inch tread. The mounting plate measures 4 1/8-inch long and 3 3/8-inch with a bolt diameter of 5/16-inch. The mounting bolt's hole spacing measures 2 3/8 inches long and 3 1/8 inches wide.