The 81A1A-B28-A13L is a 5/8" square single-turn panel control potentiometer manufactured by Bourns, designed for on-off function control applications. It features a metal shaft and bushing with consistent, smooth quality feel, and is available in single-section configuration with PC pin termination. The device utilizes a cermet element with a resistance tolerance of ±5%, supporting resistance values from 100 ohms to 1 megohm with linear taper characteristics. The potentiometer is RoHS compliant and includes an anti-rotation lug option for secure mounting on standard panel layouts. This product is ideal for audio equipment, industrial control panels, and consumer electronics requiring reliable rotary control with smooth operation and compact form factor.