When you need to change hose diameters from 4” to 5”, this is the shortest fitting available to do it. The outside diameters of the ends are 4” and 5”. Just push the hoses on and clamp in place.
Here’s a list of all fittings that can be easily connected:
13005 Dust Cap 4”
13041 Blast Gate 4” Tapered M/F
13042 Blast Gate 4” F/Threaded
13066 Blast Gate F/F 4”
13093 Splicer 4” to 4”
4” Hose
5” Hose