The workhorse of the dehydrating world, these Excalibur dehydrators can run continuously without fear of overheating. They produce a steady, even temperature that you set on the thermostat to ensure that each food item is at the ideal setting. Excaliburs heat from back-to-front. This means that you do not ever have to rotate the trays and they will all cook evenly. You can dehydrate several foods at once without worrying about the odors cross-contaminating the other foods (such as in bottom-up models). The back-to-front design, along with a controlled thermostat, eliminate case hardening. Case hardening occurs when food heats too quickly on the outside and it seals in the moisture. Even heat with the Excalibur will save you money from wasted food, and it will save time from no tray-rotation. Use your Excalibur to rise your bread dough or to make yogurt. Use it for drying flower arrangements or other craft applications. Dry your own herbs and herbal teas. Homemade beef jerky and fruit leathers are absolutely wonderful! Banana chips, apple rings, dried fruits and nuts for homemade trail mix--the applications are as endless as your imagination! Both the 9 tray and the 5 tray dehydrator comes with a free book, Preserve it Naturally, a $24.95 value.