Claustrophobia $20.00 Inside Message Blank Inside Packages of Heartstrings® cards are shrink-wrapped and sold in sets of 10 cards with envelopes. The actual card size is 4 1/4" x 5 1/2". Claustrophobia quantity Add to cart SKU: 648. Category: Christmas - Holiday. Related Products Going Downhill Without You $20.00 Across the Miles $20.00 Fat, Tired and Merry $20.00 Go to the Forest $20.00