50K Ohm square Trimpot finger adjustable trimmer 3386F-1-503T by Bourns. Bourns series 3386 cermet potentiometer, track resistance 50K Ohms Linear +/- 10% 0.5Watt Download Bourns 3386 series .pdf datasheet : Status: NOs (New Old Stock) ex RS Components : rebranded and marked as RS 187-309 RoHS compliant: no