The GD, GDN, and GDR Series of leveling casters offered by CasterStore.com by CA Kress Products, they are a solution to the age old problem of flexible movement combined with the ability of securely setting and braking a caster in a specific location. The leveling foot, once set in place, provides for stable, anti-vibrational placement. Our leveling casters can easily move up to 6,600 Lbs over four casters. Greater weight requirements may require the use of more casters. Leveling casters are being used on work stations medical, computer, communication, printing, woodworking, automation and assembly equipment. They are typically found in all manufacturing environments, including clean room and laboratory facilities. 30% Restocking on all returns per MFG.