One star is really being kind, this product is not designed to be hit by anyone over the age of 15. In a very short time the rubber 'spring' breaks. Never once kicked it either, sure it will last half the time again if you do anything but punch it.
Had it repaired, used twice and guess what? Knackered again.
By all means buy it if its for your toddler to play with so long as they won't be too rough on it. Otherwise avoid!! I'm fat and unfit, last thing you'd expect is to be able to 'knock out' a punch bag.
PS: I didn't buy this from Amazon, I'm just spreading the love :)