The 12 Volt 1 Amp Power Supply is included in the StampWorks Kit (#27297) and recommended for Stamp CI Board (#27945). Please note that Parallax BASIC Stamp® Starter Kits DO NOT include a power supply. Each BASIC Stamp Starter kit page includes a link to the recommended power supply below the product description in the "Related Products" section. Please email support@parallax.com if you have any questions regarding the proper power supply for your project.
Resources: Power Supply Recommendation Chart