Sperm plugs

I am new to breeding snakes, and I have read that if your snake is producing sperm plugs he is ready to breed. I have to adult male Ball bythons. How do I know if they are producing sperm plugs? What do they look like and where should I look?

Search "sperm plugs" here... There are some great pix floating around!

Just because he has sperm plugs does not mean he is ready to breed. I have a Hypo and an Axanthic male that I produced this year that are both around 300 grams. Both of them are producing sperm plugs, but have very small(imature hemipenes). I would not put either of these males with females. Now, if your male is 900 grams and two years old and is producing sperm plugs, Breed Away? Hope that helps.