Product review (4 stars): Functional but don't forget the battery.
This does what it is supposed to do.  I searched far and wide before finding this to allow my wife to turn on and off some medical equipment without having to get up.  It works great for that.  Unfortunately for me, right after finding this, and having not been able to find anything else before finding this, remote outlet setups have become very common and cost a lot less than this did.

The reason for the four stars is that it doesn't come with the A23 battery that it requires and nothing in the instructions tell you what battery is required.  The only way I found it was by the reviews here.  That battery is unusual and can be hard to find.  Local stores have one peg for them and that peg is empty more often than it has product.  Make sure you order the battery from Amazon when you order the switch.