This Base Plate is THE Base Plate to use with ROHN H30, H40, H50 and Channel Master 1620, 1630, 1640, 1650, 1820, 1830, 1840, 1850 Telescopic (Push-up) Masts. All the other plates have a Rod or angle piece that the Tube of the Mast centers around loosely. This Plate has a collar with a Set Screw that securely holds the Telescopic Mast Tube in place and can be in turn, cemented into the concrete Pad via the Pin provided. The word "Ground" as used in the description can be a bit of a misnomer; it does not provide a "Earth Ground" in and of itself, but rather is a junction component that rests on the ground or pad and should be Bonded to with a proper Earth Ground composed of a 5/8 inch by 8 foot Copper Clad Ground Rod as a minimum. Consult your Local Building Code and NEC for guidance to Properly Grounding your HD TV, WI-FI, Wireless Internet, Business Band, CB or Amateur Radio Antenna Installation.