The 91A1A-B28-A13L is a Model 91 single-turn panel control potentiometer manufactured by Bourns, featuring a 5/8" square form factor with in-line PC pin connections. This device utilizes a cermet element with linear taper (A-taper) and is configured with a 7/8" bushing (code 28) and metal plain bushing of 10 mm diameter × 9 mm length. The potentiometer offers resistance values ranging from 100 ohms to 1 megohm with ±5% tolerance and ±5% independent linearity, providing reliable and precise resistance control. The shaft type J configuration includes standard lengths of 16.0 mm (0.630") and 22.0 mm (0.866"), with dimensional specifications including a shaft diameter of 1.80 ± 0.25 mm and effective electrical angle of 270°. This component is RoHS compliant and suitable for applications requiring virtually infinite electrical circuit isolation and stable resistance characteristics in control and instrumentation systems.