With this blade

Thread size: 7/16" major diameter- 20 threads per inch

Mount Type: 4-Bolt Configuration

870 is sold as a combo handle and die set only

Power Trowel Stone Attachment Holder w/ Stones For Under 36" Machine 4-PK Deluxe Carpet Trimmer With this bladeStone with holder attachment for power trowel machines up to 36 inches. Use a stone with a holder attachment on each blade. Each stone holder comes with 2 x 2 x 8 inch # 6 grit stone. Grinding Stone Holder with stone attachment Under 36" Machine. Ships in 2 boxes. (4 Pack) This Power Trowel Stone Attachment Holder is a great choice for machines under 36" in size. Each holder comes with two 8x2x2 inch # 6 grit stones for efficient and consistent