The package includes four color coded receivers and a transmitter with buttons. The package comes with CT2032 for the receivers, you need to provide two AAA batteries for the transmitter.
All buttons sound fairly similar. I show how they sound in my video.
What could be better? I would nice of the receivers were even smaller. I show them in my video on 1/2" grid for size reference.
You can find it on Amazon by following this link.
Ali Julia review ★★★★★