Wouldn't it be valuable (not to mention a great selling point) if you could provide customers with a method for venting their windows without sacrificing home security? With the development of our latest window security product, Ashland is again leading the industry. Our patented DVL looks and fits like a conventional vent stop, but goes well beyond similar devices by performing double duty as a vent lock. For the first time, your customers will be able to feel just as safe as if the window was in the closed and locked position.