Actually, I think they are only 2 pounds each. I would suggest getting a pair of 5 lb. each that are adjustable, so you can go down to 2 lbs. I have some by Pro-Form that are 5 lbs. with each ankle weight containing 10 half pound iron rods that are inserted into sleeves. I can remove as many as I need to create the weight I want.
I got mine from collage.com but I have seen them available at sporting goods stores as well as at Target.