Brand new in box. Rail kit, left and right ball bearing sliders. Included with kit, velcro cable management strap, and manual.

Mounting rail kit for Dell 1U server models with 3 side mount pins only.

Included in photos for your reference, side of a Dell 1U (PE-R420) server mount pins vs a Rail Type B4 (universal 1-2U) and 08N0JT slider mount holes. From the front of server  side mount pins 1, 2, and 3 match. Pin 4 does not have a hole. Dell 2U server will not match pins 2 and 4.

The Dell PowerEdge 1U Server ReadyRails Sliding Rails Kit, part number 08N0JT A12, is a new and reliable mounting hardware for your server. With a weight capacity of 50 Kg and a rack unit height of 1U, this unit is ideal for your enterprise networking and server needs.

Additionally, this unit features a rack depth of 800 mm, two side panels, and a mount type of ReadyRails Square-Hole and Round-Hole Rack. The kit also includes an easy-to-use sliding rail system that ensures easy installation and maintenance. Trust in the brand name of Dell and enjoy the convenience and security of this high-quality mount hardware.