Cen-Tec Systems 1.25-in x 10ft Conductive Dust Collection Hose with Quick Click Tool Adapters in the Dust Collection Attachments department at Lowes.com
4 In. to 2-1/2 In. Tapered Adapter Dust Collection Reducer Fitting | eBay
Flexible Rubber Dust Collection Adapters for Tools
Compact Router Dust Collection Adapter for Plunge Base | DEWALT
Shop vac dust collection system with homemade adapters - YouTube
Amazon.com: POWERTEC 70147 4-Inch OD to 2-1/4-Inch OD Hose Reducer Adapter for Dust Collection Systems : Tools & Home Improvement