I have 200 of these things. They are normally used by companies who put the invoices inside these envelopes and stick them on packages they send to customers. The ones I have are a bit better as they have a zip lock type seal. I put one on the inside of the trunk lid. Registration and insurance card goes inside. If a thief breaks into your car, gets the registration, they know where you live and can watch when you leave and break in your house. Especially if you left the house keys in the car, and they stole them.
If anyone would like one or a couple more, pm me with your address info. I will send them to you at no charge. They are about 10"x 5"