The installation of the Waterpik XAS-649E takes a few minutes and is an easy process. The instructions said not to use teflon tape and I was dubious, but my installation was successful without leaks, so I can confirm the tape is not needed. You can easily switch between 6 spray settings with this unit. I am pleased with this product's performance, but not satisfied with the hose. The hose, after being stretched out, still does not lay properly and therefore causes the unit to sit at an odd angle in the shower that can not be adjusted easily. I intend to upgrade to a flexible, metal hose and I believe this will solve all of my issues.