A good heat mat makes the difference between success and complete failure when starting crops of tropical ancestry, including most Solanums (tomatoes, peppers, eggplants, husk cherries) and Cucurbits (squash, melons, cucumbers). The Agritape heating element is controlled by a precise controller thermostat (mat and controller sold separately). We used to sell mats that had built-in controllers, but this update with separate mat and controller offers more flexibility and longevity. Being separate items, the controller can be expanded to run multiple mats (up to 90 sq ft of mat area) by plugging a common power strip into the controller, and mats can be replaced when needed. Agritape provides an extremely uniform precise temperature over its entire surface and uses 20 watts of electricity per linear foot. Alice finally shelled out for one last season and was very impressed at the improved results compared to the cheap one-tray homeowner versions. Each heat mat comes with an aluminum grounding screen that lays down over the Agritape. Each controller has one flexible 3' tube with a temperature-sensor bulb to insert into the potting soil; set the dial to desired soil temperature. Foam insulation board may be installed under the Agritape to improve thermal efficiency, but this is not a must. Mats roll up easily for storage. Mats come in two sizes: 4' or 10' long, both lengths are 11" wide. NEW!