Vent fan adaptors for 25mm fan.

Update 2. I ended up using a 1"id hose. Part number 5643k11 from mcmaster-carr. I drilled out the holes in my part(25mm to 1in tube) with a .070 drill and my 2-56 screws PN 90272A088 screwed right into it. I drilled the hole pattern in lexan with a 2.5mm drill for the screws and I used a 3/4" drill to hog out the hole to slightly less than 1" so I didn't need the 25mm to 1in hole adaptor. Vent fan is 3cfm and seems to blow through 10ft of hose with little problem. If I wanted more flow I c