If you are planning to use a Middle Shelf, Magliner highly recommends the 40” HD Adjustable Nose, you will have the ability to use up to twelve different settings to control height positions. Top Nose Cross Bar and Adjustable Nose Cross Bar include Shelf Safety Lock receivers. Unit comes pre-drilled to accept all Nose accessories, such as: Tripod Holder, Steadi-Cam Vest Holder, Mag Monitor Arm Nose Adapter & Nose 5/8” Baby Pins.