I bought an extra extension because a co-worker ordered a duster this summer from another source for more money and it did not come with an extension. He was very disappointed so I added this to my order to give to him for next season. FYI- This model already comes with an extension if you order from here. Awesome bulb duster, well worth the extra money.
I bought three of these extensions to go along with the one extension included with the duster bulb I purchased and I am so glad I did. Even with 4 feet of tubing to go through, there was no problem for the CentroBulb duster to push the dust through the extensions. The trick I learned from YouTube was to load the Drione by pointing the wand downwards, give the bulb a few up and down shakes to load the dust and then raise the tip into the bee holes and give it one or two good puffs. Then simply reload for the next hole. Works great.