The 4-Channel Relay Module is designed for serial controllers, offering a practical solution for controlling multiple devices. With a compact size of 5.3 inches in depth and 1 inch in height, it seamlessly fits most Federal Signal Warning Lights, Serial Communication Light Bars, and other strobe lights. This module features a built-in 4-channel flasher with alternating flash patterns, providing efficient and reliable operation. Sold individually, this product offers convenience and versatility for various applications.