Colson 4 Series casters are our most popular and requested 2â€-wide casters for industrial applications, handling working loads of up to 1,250 lbs. per caster. Colson 4 Series caster rigs are manufactured in the USA for the highest available quality and quickest delivery options. Zinc plating provides an attractive and durable finish for corrosion resistance. Hollow axles with grease fittings along with grease zerk on swivel raceways allow for easy maintenance of each caster. Available in a variety of size, wheel, and accessory options, there is a 4 Series solution to accomplish any medium duty application. If you need to prevent rust be sure to check out the 4 Series Stainless Steel Series; if your application will experience shock or impact, be sure to check out the 4 Series Kingpinless Enforcer Series to prevent kingpin failures.