I'm thinking about doing this one has its winter in the northern hemisphere so chocolate is a option... usually i see this type of swap in summer... Heat+ chocolate = eww muck.
A small flat rate box is probably about the size maybe a bit smaller then a shoe box. Ill try and get some dimensions later..
ok sizes of US flat rate boxes are...
Small Box (Size of a VHS tape

or two DVD boxes stacked)
Outside:
8 11/16" x 5 7/16" x 1 3/4"
Inside:
8 5/8" x 5 3/8" x 1 5/8"
Medium Box 1 (shoe box size)
Outside:
11 1/4" x 8 3/4" x 6"
Inside:
11" x 8 1/2" x 5 1/2"
Medium Box 2
Outside:
14" x 12" x 3 1/2"
Inside:
13 5/8" x 11 7/8" x 3 3/8"
Large Box
Outside:
12 1/4" x 12 1/4" x 6"
Inside:
12" x 12" x 5 1/2"
Large Board
Game Box
Outside:
24 1/16" x 11 7/8" x 3 1/8"
Inside:
23 11/16" x 11 3/4" x 3
taken from
https://www.usps.com/ship/priority-mail-flat.htm and yep there in inches... I'm tolazy to convert them to metric
