Shatter-proof film doesn’t technically “stop” a determined burglar, but it’s one of the best tools out there for denying and delaying a break-in. Most burglaries are crimes of opportunity, relying on being able to break a window fast and get inside. Once a window is treated with quality shatter-proof film, that gets a lot harder to pull off.
An intruder expecting the glass to shatter and fall away instead runs into a tough, resilient barrier that stays put in the frame, even after multiple hits with a hammer or brick. That delay alone is often enough to trigger an alarm and send the burglar looking for an easier target elsewhere.
For the film to really work as intended, it needs to be installed with an attachment system anchoring it to the frame. Skip that step, and a strong enough impact could push the whole filmed sheet out of the frame entirely. Done right, though, shatter-proof film can turn what would’ve been a 2-second break-in into a 2-minute ordeal, and that’s usually more than enough time to stop the crime before it succeeds.