Here is the complete hardware kit needed if you are 3D printing your own Dewalt DWS779/780/718/782 Dust Collection Chute purchased from Shop Nation.
The kit includes:
(1x) Flexible Flap [size varies slightly based on saw model]
(1x) 4" section of 32mm expanding hose
(5x) Phillips Pan-Head Flap Screws
This will save you from having to source these parts individually for your print!