H2O $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". H2O quantity Add to cart SKU: 727. Categories: Gardening, Hearts. Related Products Blue Columbine $20.00 Give Peas a Chance $20.00 Hose/Snake $20.00 I Only Have Irises for You $20.00