Jacobs Patented Ratchet Locking System inside - Great bit holding and prevents bit loosening under high vibration applications.
Provides audible and tactile feedback when chuck is properly tightening.
Prevents chuck from locking open at max. capacity
Design for professional applications, 3/8" or 1/2" capacity, plastic or metal sleeve, single sleeve or double sleeve, carbide jaws(700 series) optional.