The Larsen NMOHF vehicle roof mount antenna installation hardware kit is a special application NMO mount for high frequency Motorola-style mobile antennas 0-6000 MHz in thick surfaces. Center pin is removable to function as a standard or high frequency mount. This nickel, copper and zinc alloy permanent mount is for a 3/4 inch hole in mounting surfaces up to 1/2 an inch thick. The Larsen mobile antenna mount requires cable and connector. Thread size is 1 1/8 inch - 18.