S21 Roller Ball Repair Part Photo Interrupter

A photo interrupter built to restore precise optical tracking in your S21 Roller Ball trackball, exactly where worn sensors start throwing off your aim.

This repair part is confirmed compatible with S21 Roller Ball setups. It arrives brand new and unused, ready to drop into your maintenance project. Shipping is handled via Nekopos.

Arcade trackball hardware relies on optical sensors like this one to translate physical movement into accurate digital signals, so a fresh photo interrupter can mean the difference between sluggish, erratic play and smooth, responsive control.