Common Key Fobs
Common key fobs used primarily for access to condominiums, HOA community villages, apartment buildings and community center amenities (pools, gyms and elevators) are typically passive and low frequency (125 kHz) RFID systems.
If the key fob only opens the front door of the apartment and accesses the living space, then it is a high frequency key fob.
If the key fob opens the front door, the door into the facility, and the front door into the apartment living space, then it is dual frequency (both high frequency and low frequency).
Low Frequency. Apartment buildings, doors to amenities, elevators, buildings, pools and gyms.
High Frequency. The actual apartment unit door into the living space.
Dual frequency. All of the above