Twist-to-Lock – Place sockets onto the clips to store them loosely, or twist them clockwise onto the clips to lock them in place Lock Into Tray – Lock the rail into a tray with the keyhole slot and release it by pressing the button beside the keyhole latch and sliding the rail out Rigid ABS Polymer Construction – Our rails are molded from a strong, rigid, and impact-resistant ABS polymer, giving you a stiff and well-supported product suited for supporting the weight of the sockets Universal Socket Organizer – Rail can hold 1/2 inch drive sockets and bit sockets; rail capacity may vary based on individual socket diameters Made in USA