Unisonic Technologies
ELECTRONIC TONE RINGER WITH BUILT-IN BRIDGE RECTIFIER
Contek Microelectronics
ELECTRONIC TONE RINGER WITH BUILT-IN BRIDGE RECTIFIER
STMicroelectronics
Electronic two-tone ringer
Wing Shing International Group
Electronic Two-Tone Ringer
Unisonic Technologies
ELECTRONIC TONE RINGER WITH BUILT-IN BRIDGE RECTIFIER
Unisonic Technologies
ELECTRONIC TONE RINGER WITH BUILT-IN BRIDGE RECTIFIER