I bought the 22". Easy enough to put together. I have it paired with a Scheppach Petrol Pressure Washer. Tested it out on my patio slabs that were really green will algae, and did a fabulous job. Surprisingly quiet and keeps the mess to a minimum. Not for use on raised edges as you will likely damage the spinning nozzles, but this really comes into its own on block paving. I wish I'd invested in one years ago. Not cheap, but you get what you pay for, and this is worth every penny to me in the time and mess it saves. Don't lend it to any mates, you'll never get it back.