Primer cam Index Stop Switch for Dillon Precision XL650 and SL-900 Progressive Reloading Press. The switch moves to turn ON and OFF the index by passing the indexing lever on the primer feed assembly. Integrated spring ball works as clickable position capture. Use the factory screw to install. Material for the base is 6082 aluminium and material for the ramp is Delrin (POM-C). Spare ramps can be ordered separately. Super simple install. Just unscrew original primer cam and use same bolt to attach this stop switch.