| Capacitive fingerprint sensor | Reads patterns in the ridges and valleys of a finger using changes in electrical capacitance. | Convenient key-free access; the sensor can be compact and integrated into a handle or lock panel. | Recognition may be affected by very wet, dirty, worn, or damaged fingers. Performance differs by sensor and lock design. | Check enrollment capacity, response in the intended location, and whether the sensor is protected from rain and direct exposure. |
| Optical fingerprint sensor | Captures an image of the fingerprint, typically using light and an image sensor. | Uses an established fingerprint-imaging approach and can provide a visible sensing surface. | Image quality can be affected by dirt, moisture, lighting, or a damaged finger; implementation varies between locks. | Ask how the sensor performs in the lock’s installation environment and whether the manufacturer provides clear cleaning and care guidance. |
| PIN code | Unlocks the door after the user enters a stored numeric code on a keypad. | Useful when a fingerprint cannot be read and for temporary access if the lock supports separate or changeable codes. | Codes can be observed, shared, or guessed if they are weak or reused. Keypad usability may vary in poor lighting. | Look for code management, incorrect-entry lockout settings, and a keypad that is easy to use without revealing the code. |
| Mechanical key | Operates a physical cylinder independently of fingerprint recognition, where a key override is provided. | Can provide an alternative if the electronic controls or batteries fail. | Not every model includes a key cylinder; keys can be lost, copied, or difficult to access during an emergency. | Confirm that a physical key override is included, where the keyhole is located, and how spare keys should be stored securely. |
| IC card or proximity card | Unlocks the door when a registered card or token is presented to the reader. | Simple for users who prefer not to enter a code; cards can often be added or removed through lock settings. | A card can be misplaced or shared, and compatibility depends on the lock and card technology. | Check the supported card type, card-management process, and what to do if a registered card is lost. |
| Phone app or Bluetooth | Uses a compatible phone and wireless connection for unlocking or managing access, depending on the model. | May support remote or temporary access features when the lock and its network setup provide them. | Availability can depend on phone battery, connectivity, app support, and account security; Bluetooth alone does not provide internet access. | Check whether remote access requires an additional gateway, which phones are supported, and how access works during an internet outage. |
| Emergency external power | Supplies temporary power to a lock with depleted internal batteries through a supported external power port. | Can help power the lock long enough to use an authorized unlocking method. | It supplies power; it is not itself an unlocking credential. The port and supported power source vary by model. | Confirm the port type, recommended power source, location of the port, and which credential is still required after power is supplied. |