An NMO antenna mount is a type of mounting system for mobile antennas, commonly used in vehicles. NMO stands for "New Motorola," referring to the mount style originally developed by Motorola. Here are some key features of NMO antenna mounts:

• They are designed for through-hole installation, typically requiring a 3/4 inch hole in the vehicle's body or roof
• NMO mounts provide a secure and waterproof connection for the antenna
• They are often used with VHF, UHF, and dual-band antennas for applications such as amateur radio, public safety, and fleet communications
• NMO mounts are known for their ease of installation and the ability to quickly change antennas without removing the entire mount

NMO mounts are popular because they offer a sturdy, low-profile mounting solution that maintains the vehicle's aesthetics while providing excellent performance for mobile communications.