The document describes the SE30A series of brushless servo amplifiers. It includes models SE10A8, SE10A20, SE10A40, SE30A8, SE30A20, and SE30A40. The amplifiers are designed to drive brushless motors with 3 phase sine wave current using encoder feedback for sinusoidal commutation. They have features like surface mount technology, small size, low cost, optical isolation, and DIP switch selectable operating modes. The document provides detailed specifications, pinout diagrams, switch and potentiometer functions, and application notes for setup and use.