Product review (4 stars): Company was prompt and price was good. I have to replace the valve every 18 ...
Company was prompt and price was good.  I have to replace the valve every 18 months or so.  That is aprilaire's and the manufacturer's issue.  This supplier was great.

Remember to check the flow direction.  If you need to reverse the valve for mounting, just loosen the nut on the end of the solenoid housing,  turn the mounting flange and retighten the bolt.