Telephone Ringer Phone Amplifier compatible with Ideal Solution compatible with the Hard of Hearing Installation: 1.Please connet the C/O ring plug with ringer's jack. 2.The ringer's plug connet with telephone. 3.There are high,low switches compatible with your selections. Features: Flashing light alerts you of incoming calls in quiet environments. It has a light and switch to select between a high and low frequency ringer sound. The switch has 2 positions: One compatible with the high frequency ringer sound and the other compatible with the lower frequency ringer sound. Easy to easy. Operates with simple connection to phone line. compatible with Ideal solution compatible with the hard of hearing, or compatible with use in noisy environments, indeed anywhere indoors. Telephone Ringer only, other accessories demo in the picture are not included! Specification: Material: Plastic Color: White Dimension: 97x57x26mm/ 3.82x2.24x1.02in Quantity: 1 Pc Note: 1.No retail package. 2.Please allow 0-1cm error due to manual measurement. plz make sure you do not mind becompatible withe you bid. 3.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: 1 x Telephone Ringer