This is again a very simple astable multivibrator circuit using NE555. The circuit produces a sound that somewhat sounds like a raindrop. This is a very basic electronic kit project for electronics beginners and hobbyists. Anyone with basic electronics and soldering skills can build this easily.
This is the schematic of the kit:
Check out all the assembly images below. You can see the images on Flickr also.
The kit after full assembly looks like this:
You can find similar DIY kits assembly at www.kitstv.com.