The pack of two 6 x 3" Ground Glider Caster with Brake from RocknRoller MultiCart is a replacement caster system with nuts and lock washers for the R14G and R16RT utility carts. Each caster features low-profile, no-flat tires around a durable and lightweight hub. When in use, they provide low rolling resistance, pneumatic-like cushioning, and wide load dispersion over soft terrain.