Sealed beam headlights were a common type of headlight used in classic cars. They were made up of a single bulb and lens, which were sealed together as a single unit. This made them easy to replace and maintain since you could simply swap out the entire unit rather than having to replace individual components. However, sealed beam headlights weren’t as bright or efficient as more modern headlight designs, such as halogen or LED headlights (via Car & Driver).
Plus, they didn’t offer as much customization or variety in terms of beam patterns or brightness levels. Despite these drawbacks, many classic car enthusiasts still prefer sealed beam headlights for their period correctness and authenticity. They offer a unique look and feel that can’t be replicated by more modern headlight designs.