Ten cards, five of each color gremlin.  You put all the red gremlins face up and the green gremlins face down into the same pile.  You overhand shuffle the cards, even the spectator can shuffle them.   You then put the cards behind your back, count off the top five cards into one hand, bring the cards back to the table and spread each pack.  Upon spreading them out, there will be an equal number cards face up in each hand and the face up cards in one hand will be all red and the other will be all green.
 
CONDITION NOTES:  Very nice condition for its age. Would make a great display piece or performance trick.