Four 4.25 x 5.5" folded note cards with blank interiors.  Set contains one of each design:  

Ruby-Throated Hummingbird w/ Light Olive envelope
Rufus Hummingbird w/ Sage Gray envelope
Anna’s Hummingbird w/ Powder Pink envelope
Allen’s Humminbird w/ Papaya envelope

Printed on 120# eggshell white card stock.  Each card is individually packaged in a clear protective cellophane slip cover; the four are bundled together with bakers twine, suitable for gifting.