Like these ones sold by ERIC - here.
Two pairs are blue and two pairs are white with a pattern - I am afraid that the white ones are bit stained though they are clean .
They fitted Ds2 when he was about 4-5 years and they really do hold the wee like a nappy so they are good if you are training your child but need a bit of insurance when you are going out somewhere where it won't do to wee on the carpet .
I know they don't sound that attractive but I thought they might be useful to anyone attempting potty training with a special needs child as they are quite expensive to buy. I will happy send them free of charge to anyone who can use them.