Wheelock's loud bell phone ringers are attention-getting telephone alerts designed for use in noisy locations and/or for medium to large area coverage. Perfect for both Indoor or Outdoor apllications. Typical applications would be factories, repair shops, printing shops, loading platforms, and warehouses. TelBells utilize a durable, high torque, permanent magnet motor-driven mechanism and 6" low frequency aluminum bell shell to produce a higher sound output and lower resonant frequency than conventional mechanical bells. TelBells include an extremely adjustable, tamper-resistant volume control, and are designed for both indoor and outdoor applications.