Syntax:

<device-class>a_class_name</device-class>

[Optional]

It specifies the implementation class. The class must implement the org.zkoss.zk.device.Device interface. Instead of implementing it from scratch, you can derive from the proper implementation, such as org.zkoss.zk.device.AjaxDevice.

<device-config>
    <device-type>ajax</device-type>
    <device-class>my.MyAjaxDevice</device-class>
</device-config>