To prevent tampering and build public confidence, Robert Heilman invented a relatively simple closure mechanism, dubbed the HeiLighter, which is contained in what looks like a standard screw-on lid. Screwing the device on a bottle or jar during capping arms the device. The next time it is opened, a colored ink or paste flows out of a reservoir and into a sealed area to create an irreversible and visible display on the lid. It works regardless of what's inside the container or whether it is vacuum packed, or under slight or neutral pressure.
The device consists of three elements: a transparent threaded cap, a metal actuator panel inserted inside the transparent cap, and an indicating material sandwiched between the cap and actuator. A round area on the actuator is pulled down by vacuum during assembly and a dab of indicator put on it. Lugs on the lid hold down the round area or "button" after assembly. Twisting the lid open by the consumer or vandal frees the actuator from the lugs, it snaps back to its original shape and pushes indicating fluid into a visible window.
This easy-to-use patented device eliminates expensive tamper bands, shrink bands, film-wrapping for cartons, and blister packs. It can be used for a wide variety of food products or promotional contests. With a black indicator and the product's bar code printed on the lid, cashiers couldn't scan already opened jars and bottles because the indicator would spoil the bar code. This would prevent stores from selling vandalized bottles and jars.