Listen and follow The Wirecutter ShowApple Podcasts | Spotify | Amazon Music | YouTube | iHeartRadioCar accidents where a vehicle is submerged in water or erupts into deadly flame are rare. But a simple tool to break your own car window could be life-saving in such an emergency. The only catch: not all car windows are created equal.This week, Rosie talks to Wirecutter editor and emergency preparedness expert Jen Gushue about the high-stakes world of car glass breakers. Jen enlisted a firefighter to help smash dozens of real car windows to find out which tools actually work when put to the test on different types of glass.This episode coversThe difference between tempered and laminated glass: Traditional tempered glass is designed to shatter into small, dull pieces for safety, while modern laminated glass consists of a plastic interlayer sandwiched between two glass sheets. Laminated glass is nearly impossible to break with standard tools.How to identify what’s in your own vehicle: A small key in the corner of your car window should contain information about the type of glass it's made of. You can also look down at the window from above.The specific tools that work for each scenario: While portable spring-loaded tools are highly effective on tempered windows, only specialized tools are capable of punching through the reinforced laminated glass found in many newer vehicles.Be sure to read Jen’s guide for more details on how to tell what kind of glass is in your vehicle.Products we recommendA spring-loaded, hand-protecting tempered-glass breakerLifehammer EvolutionThe long handle keeps your hand from pushing into shattered glass, and the spring-loaded ceramic tip is easy to activate.$37 from Amazon(pack of two)$20 from WalmartThe only practical laminated-glass cutterLifeline Evac-ProIf your car has laminated-glass windows, a punch tool won’t work. Saw through the glass with this specialized blade.$239 from LifelineA handy keychain that works on tempered glass (with compromises)ResqmePortable and compact, the popular Resqme is effective, but it works only on tempered glass. And as we learned in testing, you might shred your hand on the broken glass.$8 from Amazon$10 from Walmart