Craftsman 11 pc socket set is a cost-effective solution :
1) 5-13mm 1/4 small sockets marked MM, 
2) a 1/4" drive ratchet,
3) a 1/4" extension by 1 1/2" length.
4) Laying flat these are 6 3/4" Wide X 5" Deep X 1 3/8" Tall