The SF503UL Neck Lanyard Pendant and SF504UL Wristband Pendant feature the great range and reliability of 900 MHz in a small, waterproof package. The pendants can be worn in the shower or bathtub, outside in the rain, or other environments where they may be splashed with water or momentarily submerged.

The pendants have a single-button design with "press and one-second hold" activation, making them easy to use but resistant to false alarms. When a pendant is activated, it vibrates briefly and its red LED blinks rapidly for five seconds, then blinks slowly until the alarm is cleared. Alarms may be cleared by placing an RP500 Alarm Clearance Card over the button, or by a sequence of button presses.

The pendant transmitters are especially suited for assisted living installations. They feature a fully supervised RF link to ensure reliability. The built-in LED flashes with all transmissions, including supervision, so the user can see that the transmitter is still functioning.