Touch it Poland game

Test yourself and, without using your eyesight, try to recognise the object on the card. There are 4 shapes on the front of the card and a convex outline of one of them on the reverse. Your task is to guess which of the 4 shapes is on the reverse side. Will you be able to recognise them using only your sense of touch? 

Express version of the rules:

1. Pick one card from the stack without looking at the reverse.
2. Using touch, try to identify the correct object on the reverse side. 
3. The player who knows the answer shouts Stop!, puts the card down and waits for the rest.
4. The last player must immediately put the card down. 
5. The fastest player scores 2 points for a good answer.