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 temporarily removing the magnet-attached ramp thus allowing passing the indexing lever on the primer feed assembly. Use the factory screw to install. Material for the base is 6082 aluminium and material for the ramp is Nylon. Spare ramps can be ordered separately. Super simple install. Just unscrew original primer cam and use same bolt to attach this stop switch.