one per ounce of the envelope, use a regular kitchen scale to measure.
it probably won't be more then 3 stamps, but it depends on how heavy your flash drive is.
I'm bored, and we all love jokes, right?
While we're on the topic of jokes, did you hear about the guy who got the entire left side of his body removed in a surgery?
yeah, he's all right now.
hahahahaa.
have a great day!