This comes with one transmitter and four receivers. Once you press the remote, a receiver sound beeps and the items lights up. The remote's range reaches up to 30 METERS, so if you're one to throw your keys out the window, you're in luck.
Promising review: "Do you have kids? We have three of them. By the time I get home from a long day at work, sometimes I just need a little Netflix or Amazon Prime. Before I got these, there was this hellish period of 'you've got to be kidding me? What do you mean you don't remember where you put it?!?!'. Sure, we had a designated basket where the remotes should go, but they'd be under the couch, under a blanket, in the next room, etc. Now, all I do is click a button on the base remote and the fob chimes away and we have fun finding the cussed little devices. Sure, they still end up in every conceivable unusual spot, but now we can find them." —UkuleleJoe
Get it from Amazon for $19.99.