chatter box and block off

Does any one here use a chatter box? I am not going to use it to talk to others I want to plug it into my MP3 player. I could use the earbuds that it came with but those bother me after 30 minutes or so. Can any one tell me if the box uses a 3.5 mm plug in? If so, what is the model and where did you get it?

Also i looked a few places for those block off plates and can't find them. Can some one point me in the right direction?