I think this is what's going to happen - if you send chip/chips in bubble mailer ( Flat ) - you run the risk of haveing it destroyed going thru the machines or damaged - if you use conformation delivery - Make sure the mailer is 3/4' thick or thicker ( use a wade of paper inside mailer to do this ( works for me ) other wise who ever gets it will be paying the difference of Priority mail $2 to $3+ Postage due - I already have - I got 5 in one day - gets costly