REDIboss78 gas powered post driver with 3 1/8″ guide tube; powered by authentic HONDA gx35 engine. Purchase of the REDIboss78 post driver includes the REDIslvboss78 reducer for driving smaller posts up to 2”. This is the largest & strongest gas powered post driver on the market! We offer the best 3 year warranty on the market! You can drive a wide variety of post sizes with just one driver! Reducer sleeves in a variety of sizes available for purchase separately.