Carbon Fiber PET shell.

16 minutes minimum spin time guaranteed

Tungsten Alloy counterweights - 22 mm diameter, 7 mm thickness (17 gm/cm^3 density) . These are not tungsten carbide, but tungsten alloy - heavier

R188 Stainless bearing for maximum spin time - individually selected out of large batches for best performance

R188 to 608 adapter (bearings easily interchangeable)

Brass center bearing caps

Can laser engrave any text down one arm of the spinner. In PET-CF plastic - this results in engraving. If use Nylon as shell material, then it marks in a lighter color (in this case marking not engraving). Your choice when you purchase

Total weight 179gm