A headerless heat exchanger has a core comprised of a stack of flat tubes of rectangular cross section through which a first heat exchange fluid passes. Purchase orders from customers are selectively fulfilled and products are shipped to the customers either by the system for online sales with automatic rebate and coupon redemption or by other merchant or manufacturer environments. The waterborne epoxy composition cures under normal conditions and adheres to surfaces including masonry, concrete and metal. The valve is collapsible for containment within a catheter and expandable in situ when deployed to occlude the lumen. The illustrated card allows users especially children to make the illustrated card by themselves and children can be trained to arrange the ornamentation with different colors for improving chromatological and fine-motor skills. For each of the compliant sealing means there is a pair of clamping members for releasably clamping the sealing means to form a substantially moisture-tight seal.