A true convection microwave has a high velocity forced air fan to circulate the hot air uniformly, therefore a convection microwave trim kit needs a "fan box" to remove the energy it creates.

Without a "fan box", the life of the microwave will be greatly reduced.

With the expensive price of all convection microwaves, a short life span will make for an unhappy consumer.

TrimKits USA's convection microwave trim kits not only include a "fan box", but also includes a thermostat that is set to 109.4° F, a squirrel cage fan and a complete hardware kit with all necessary supplies for installation.