SolidTrax Track Dolly Wheels, Set of 4, for Modus System

Complete set of four SolidTrax quad wheel assemblies for building atrack dolly using the Modus platform. The set includes 16polyurethane wheels and 32 precision bearings total, giving youeverything needed to convert a Modus platform into a smooth-rollingtrack dolly. Each assembly is fitted with dual ball bearing sets for smooth rotationon both straight and curved tracks. They fit tracks from 3/4” to 1.5”and mount to the Modus platform with included knobs. Whenmounted, the track spacing is 7-1/4” (184mm) on center. This is the wheel set only. For a complete ready-to-use track dollysystem, see the Modus Track Dolly System which includes both theplatform and wheel sets. If you want to build from scratch, pair thisset with a Modus platform (sold separately). Steel, aluminum, or rigid PVC piping is recommended for trackmaterial. Specs: Quantity: 4 quad wheel assemblies (16 wheels, 32 bearings) Track compatibility: 3/4” to 1.5” Track spacing on Modus: 7-1/4" (184mm) on center Wheel size: 5