The phrase "a class of devices" is correct and usable in written English.
It can be used when referring to a specific category or group of devices that share common characteristics or functions.
Example: "In the field of technology, a class of devices known as smart home gadgets has gained immense popularity."
Alternatives: "a category of devices" or "a group of devices".
Nuclear reactor, any of a class of devices that can initiate and control a self-sustaining series of nuclear fissions.
Electric motor, any of a class of devices that convert electrical energy to mechanical energy, usually by employing electromagnetic phenomena.
Battery, in electricity and electrochemistry, any of a class of devices that convert chemical energy directly into electrical energy.
Stingray, manufactured by the Delaware-based Harris Corporation, is one of a class of devices known as "cell site simulators" or "IMSI-catchers".
The Grasshopper is 10-story tall vertical takeoff vertical landing rocket (VTVL) – a class of devices that SpaceX are aiming to make reliable enough for routine use.
This configuration is used in beam-focusing devices as well as in a class of devices called magnetrons (see the section Magnetrons).
This week's App Smart was about apps you may like to try out on your new Android tablet — a class of device that is really making a splash in the mobile computing market to rival the iPad.
A growing category will be internet-connected monitors for "smart metering", video surveilance, maintenance, building automation, healthcare and consumer electronics – a class of device known as "machine-to-machine" (M2M) systems which communicate directly to other computers over the internet without the mediation of humans.
Artificial leaves aren't new: they're a class of device which passively converts light into power for various purposes.
It's a class of device that is aimed at simplicity of use, portability and the ability to allow the user to sit down and type pretty much wherever they are without having to wait for a full-scale notebook PC to boot up or wake up from sleep mode.
A class of such devices for self-diagnosis is the natural extension of our work and having such a device would enable early detection of diseases, such as cancers or internal bleeding, thus potentially saving the lives of many.
