So I purchased this surface cleaner without realizing it had 3 heads instead of two. The rule of thumb is you want ~2gpm per head to efficiently drive the unit and get good results. I have a 4400psi 4GPM Dirt Laser and the first time I went to use this, I was really let down by the results. It hadn't occurred to me that having the third head cut the pressure down so much. According to my gauge, I was only getting about 700psi from the unit. Unfortunately at this point, I had it over a month and it was too late to return it. After extensive research, I found that the General Pump Hammerhead 18" Replacement Surface Cleaner Spray Arm (part #2530052) fits this unit perfectly. Once I replaced the 3-head arm with this replacement 2-head arm, it works phenomenally. I can't deduct stars because the product itself isn't bad, I just don't have the volume from my power washer to support it. If you are in a similar boat, the $40 replacement head is much better than spending another $250+ on another unit. To remove the head, simply use snap ring pliers and remove the snap ring, then pull the head and it will come out with the rotating assembly. Use a couple wrenches or a vice and separate them. Don’t forget Teflon tape when you put the new head onI will say it seems built well. I went to the orange home improvement store and purchased stainless hardware to use in place of the pins that hold the machine together. This gave it a much more sturdy and less rattly feel. The gun works well and the machine hasn't leaked or rusted yet.Moral of the story, make sure you have one hell of a power washer to run the 3 heads. If you do, you'll like this surface cleaner. I hope this helps someone.
B 
