Product review (2 stars): Get what you'll need at a hardware store.  Don't buy this.
I purchased this to go along with my whole house humidifier cause Honeywell doesn't give you all the stuff you need with the humidifier.  However, read up on what is included and what is not.  I bought a seperate humidistat because I thought I needed one but there is actually one in the humidifier package.  Most modern furnaces don't need the separate transformer and sail switch that come in this kit. You can find the schematics online for your furnace if you don't have the manual it came with to wire to the 24v output on the control board in the furnace unit and not have to use the sail switch and 24v transformer. Hence, I'd recommend buying the water tubes and ducting at a hardware store. I would imagine that if I'd thought ahead far enough I could have found the 5" duct and hoses for around $20 or less and saved myself some money. My mistake is your lesson here I guess.