I actually purchased the single sensory ball first, and my 11mth old son loved it so much i have purchased the 4pk for xmas.It has now become his MOST FAVOURITE thing and always goes for this out of his box first,casting aside ALL other toys to get to it! He bites it constantly (no bits come off) he rolls on top of it,launches it at the cat and it takes all of it. I have spent a small fortune on musical/spinning/all singing and dancing toys and who would have thought a good old fashioned ball would give hours of pleasure ? The 4pk are obviously smaller than the single 1,but they are still a good size.Big enough for small hands anyway and i feel this pack is better value for money.
These balls are nice bright colours, squishy, with rounded spikes. My sons seen to enjoy playing with them and they are nice and light for babies to roll and their around. The only thing is that they are bigger than I expected - each ball is about 10cm diameter so they are too big for party bags and so one pack has been returned.
My 1 year old son loves these. Very tactile, very tough and very easy to clean. The easy cleaning bit is handy as I found one ball in the dogs mouth as he tried to get all of the dried up Farley's Rusk off the ball :)