Testing definitely shows lower pressure vs OEM product
I needed a replacement hose/handle assembly for my Waterpik WP-100 due to a broken hose.  I considered the OEM from Waterpik and the WyFun from Amazon and decided on the WyFun because of the lower price.  Actually, the Waterpik model is only about $3 more but Waterpik charges $5.95 for shipping so there’s a $9+ difference.  Many of the reviews say the pressure from the WyFun is lower than the original Waterpik but I thought I’d give it a try anyway.  I definitely noticed a reduction in pressure when I first tried it and over time, decided that it wasn’t enough so I bit the bullet and ordered the OEM from Waterpik.  One of the first things I noticed in comparing the two was that the intake hole in the fitting that connects to the main unit was smaller on the WyFun unit vs the Waterpik by about 1mm. I then decided to give the two a somewhat scientific pressure test.  I timed how long it took to transfer 12 oz. of water from the Waterpik unit (set on “10”) to a measuring cup.  I did three tests for each hose/handle assembly.  The WyFun averaged slightly over 1:20 (one minute, 20 seconds) for the transfer, the Waterpik was under 1:05.  This tells me that the Waterpik hose/handle moves water about 23% faster than the WyFun.  I’m not hydraulics engineer but I think this equates to 23% more pressure from the Waterpik OEM hose/handle.  The WyFun unit otherwise worked OK for me and if you normally run at a lower pressure, it’s probably suitable, but if you want full pressure, the Waterpik OEM is the way to go.  As a note, I did this testing during the covid-19 crisis under the stay-at-home orders so it gave me something to do.
Rating: 2 stars