TCP Global 5/8" to 5/16" DA Thread Adapter Converts 3" to 6" Polisher Pad Backing Plates to 5/16" Threads for Dual-Action Buffers & Sanders DA Adapter so you can attach 5/8" Rotary Backing Plates Converts from 5/8" rotary backing plate thread to 5/16" DA thread Allows you to use rotary backing plates with your DA polisher D.A. Adapter for 3" Backing Plate for 3" Buffing & Sanding Pads