Product review (5 stars): OEM valve and easy to install
My Aprilaire humidifier is 15-20 years old but this vavle was still an identical replacement part for the original valve.  Even though this new vavle had a manufacturer's name other than Aprilaire on the package, it looked, installed and operated exactly like the original valve.  I haven't performed any maintenance on my humidifier before so I had no previous knowledge on how to install the valve.  I purchased an Aprilaire Humidifier maintenance kit in addition to this valve and installed both at the same time in about an hour.  I did not have to modify anything for this valve to install and operate correctly, I just followed the simple instructions.  One word of advice, before ordering this vavle loosen the supply side fitting to your existing valve and make sure that water is getting to it.  Many of the humidifier installation kits include only a "puncture" collar to connect to a water line and these devices are easily clogged by small sediment in the lines.  This was not my problem as I replaced that device with a ballcock valve when replacing my water heater a few years agol