Installing the Multiple 4.2.5 Defense offers 216 pages and goes over how the 4.2.5 Defense is built around a basic 8-man front with 4 down linemen, 2 inside linebackers, 2 outside inverts, and a 3-deep secondary. Coach Campbell has also included drills that will take you through tackling techniques, pursuit drills, and an abundance of position techniques. $19.95