The Struthers-Dunn 388 series time delay relays are square base, bladed versions designed for various industrial applications. These relays offer on-delay, off-delay, and interval functions, catering to diverse timing needs. Available with AC or DC inputs and up to three poles, the 388 series provides flexibility in control circuits. The timing circuit is oscillator-based, with both fixed time and externally adjustable versions available. Socket and flange mount options ensure compatibility with different panel configurations. These relays are suitable for applications requiring precise timing control in automation, process control, and other industrial settings.