D Line Sled Drills

These D-Linemen are practicing the run first technique of Step - Punch - Extend from a 4-Point Stance. They continue to drive the sled in this video as a way of engraining aggressiveness, but would stop 1-2 yards deep in a game to find the ball and prevent gaps in the line.
Note how low they stay, the speed with which they get off the ball, and the way they extend their arms after initial contact.