How do I change the metal pins of the Reactor-Ready drop-in coupling or the stirrer guide cap? The three coupling pins on each of the stirrer drive drop-in coupling and the stirrer guide should be regularly inspected. These pins can wear over time and require periodic replacement. For Reactor-Ready and Reactor-Ready Duo, the relevant part numbers are: RR121066: Stirrer Drive Drop-in Coupling S/S Pins (Pack of 3) RR121067: Stirrer Drive Drop-in Coupling Dowel Pin (Pack of 1) RR121068: Stirrer Drive Drop-in Coupling Snap Ring B24 10 mm (Pack of 1) RR121062: Stirrer Guide Cap S/S Pins (Pack of 3) RR121099: Stirrer Guide Metal Cap Grub Screw (Pack of 1) We can send you a guide explaining how to change the pins; please contact Technical Support. N.B. For Reactor-Ready Pilot, instead of RR121068 you will need RR121142: Stirrer Drive Drop-in Coupling Snap Ring B34 16 mm.