Ridgid 2.5" Shop Vacuum hose adapters! My dad was looking for a few different adapters. The ridgid brand stuff is junk and doesn't even work with their own hoses, let alone anyone
Ridgid 31743 Vt1755 Vacuum Hose to Hose Adaptor Kit : Amazon.ca: Tools & Home Improvement
Vacuum Hose Adapter BLACK+DECKER 5-inch Random Orbit Sander to Rigid Shop Vac | eBay