Fully 3D machined from solid 6061 aluminum bar.
 
Billet rail idler wheels available in multiple bearing sizes.  The 5.625 is very commonly found as the front rail idler wheels on many newer Polaris models and use the 6004 bearing in that application.   Fully 3D machined from solid 6061 aluminum bar. 

6004 bearing size = 42mm x 12mm x 20mm
 
Pricing in Cdn dollars.