General description You will receive 4 pieces of garage door opener remote controls compatible with M12 garage door remote transmitters for automatic swing and sliding door openers. These wireless transmitter keychain security door controllers meet your usage needs and operate effectively. Technical specifications Compatibility: M12 garage door remote transmitter Operating frequency: 433.92 MHz Operating range: up to 200 feet Material: ABS Measurement allowed error: +/- 1-3 cm Compatibility and accessories Can operate multiple door openers within control range Supports control of four swing door openers and one sliding door motor Can control two sliding door motors by adding two ERM12 on each control board Usage Ensure the garage door opener is completely closed before starting remote programming Simple programming with clear instructions provided Other information Safe and reliable operation with low power consumption for long battery life (built-in dry battery) Rolling code