USPS First class for certain items?

Is it possible to have USPS first class envelope shipping as an option for certain items?
I have a handful that I can ship like this so it would be nice to offer that shipping option instead of the $10 UPS charge.

Thanks for any advice.

If you don't use USPS for anything else, you could select only the First Class Envelope for that shipping method, and then use Restrict Shipping Methods to limit USPS to appear when only those items are in the cart.