REDIbttmboss is a complete post driver bottom assembly with 3 1/8″ guide tube. This is the bottom half of the REDIboss78 driver and can be easily added to your REDIclassic52 driver when you want to drive larger posts. Perfect for increasing the versatility of your REDIclassic52 driver. The bottom assemblies on each model are interchangeable by simply removing 4 bolts and switching out! Purchase includes a 2 1/4″ REDIboss78 friction fit reducer sleeve. Other sizes of reducer sleeves available for purchase separately.