Winco SSDB-20, 20-Quart 11-7/8" x 10- 5/8" x 11-7/16" Master Cook Commercial Grade Stainless Steel Double Boiler With Cover, NSF will be an extremely useful addition to your cookware collection that will help you to melt caramel and chocolate and cook delicate sauces. This NSF listed double boiler set by Winco provides even and thorough heat distribution at lower temperatures. It is constructed from 18-8 stainless steel with aluminum core. The double boiler includes a pot for boiling water, a perforated insert and a matching lid for better heat retention. The aluminum double boiler with perforated strainer insert will surprise you with its amazing quality that will last you for ages.