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 Where the Heart Goes, Flowers Grow $20.00 We Sing in Circles $20.00 A New Pea $20.00 I Only Have Irises for You $20.00