RediDriver REDIslvtpost78 1 3/4″ Reducer sleeve for REDIboss78RediDriver REDIslvtpost78 1 3 4 Reducer sleeve for REDIboss78 REDIslvtpost78 is a 1 3 4 reducer sleeve to be used inside the 3 1 8 guide tube of the REDIboss78 driver. This sleeve will reduce the inside diameter of the 3 1 8 guide tube down to a 1 3 4 inside diameter for more efficient driving of t posts. The ID of this reducer sleeve is slightly less than the REDIslvboss for a better fit around t posts. No need for other complicated accessories.