I initially bought one from an online vendor and now wish I hadn't. From them I paid around $90 plus shipping and all I really needed to do was go buy it from Lowes or Home Depot for $44 plus some rope and an eye bolt. They are advertised as the "Lake Rake" online but all it is, is a 3' landscaping rake.
That being said, it does work amazingly well and that's why I decided to fasten 3 of them together to make a 9' version and cover more ground per pass of the rake. It works well for bottom dredging or as a floating skimmer by zip tying the pool noodles to it.