Automatic Center Punch Strikes Surface W/o Hammer Spring Loaded Window Breaker Automatic Center Punch Heat Treated Alloy Steel Point Brass Body; Chrome Plated Tip Knurled Handle For Sure Grip Automatically Strikes A Surface With Powerful Spring Action When Pressed 5 Overall Length With A  Diameter Body Great For Punching; Screwing Holes And Starting Drilling; Screwing Or Riveting Holes One-hand Operation And Easy To Carry