A Bosch stacking kit can be purchased from Best Buy, Lowe's, and Sears, as of 2015. These stores offer stacking kits on their websites and at store locations.
Best Buy sells Bosch stacking kits for select 24-inch washers and dryers. They are delivered free and are price match guaranteed. Lowe’s sells the 24-inch stacking kit with a pullout tray, and offers free store pickup and truck delivery. Sears sells the Bosch WTZ20410 laundry stacking kit and offers live chat support from a Sears expert.
eBay has auction listings for Bosch stacking kits. However, prices and availability on eBay are subject to change at any time.