There are different options for screen protectors, but the strongest ones are typically made of tempered glass. These screen protectors are thicker and more durable than plastic ones, and they can effectively absorb impacts and prevent scratches and cracks on your phone screen. Some high-end tempered glass screen protectors can even withstand extreme forces, such as hammer strikes and drops from several feet. However, it's worth noting that no screen protector is completely indestructible, and even the strongest models may fail in certain situations. Therefore, it's essential to choose a reputable and reliable brand and installation method, and to handle your phone with care to minimize the risk of damage.