It feels like bubble wrap to touch, the sound is like as if you tap your pen on a desk. So it isn't great in that respect. After about 100 clicks (or so it feels) you hear a random sound, like a door bell or a dog bark etc etc. It is a daft stocking filler, now that it has been reduced to £2.99 you can't really complain too much.
This is reasonable if you just want it as a cool keyring which does something. But as a gadget which is meant to pop like bubblewrap it's very disappointing and waste of money as the sound is too quiet and doesn't sound much like bubblewrap at all. The quality of the item isn't very strong and the pop just isnt very real. The actual chain on the keyring is also quite weak. Buy as a reasonable keyring, but not as a gadget which you want to aslways show off with- as it's disappointing and doesn't really display itself very well. Price is a little too high too. I wouldn't recommend this much, unless you really want it..