Check the listing for details. 50W 300R Ohm Wirewound Ceramic Potentiometer Variable Rheostat Resistor Wth Knob. Condition: New. Listed at 25.05 USD. Product Name: Wirewound Ceramic Potentiometer Resistance Value: 300R OhmPower：50WTolerance: +/-5%Terminals Number: 3Features: Round ShaftTotal Size: 63 x 67mm/ 2.48 x 2.64 inch (D * H)Screw Thread Dia: 10mm/0.39 inchShaft Diameter: 6mm/0.23 inchShaft Length(do not include the Screw Thread parts):14.7mm/0.58 inchShaft Total Length：30mm/1.18 inchPackage Content:1 x Wirewound Ceramic Potentiometer Knobs Size: 18.8 x 30mm/ 0.74 x 1.18 inch(H*D)300R Ohm, 3 Terminals, Single Linear, Suits Most Standard Knobs.（this item include Knobs)Material：Ceramic MetalControl the electrical resistance of a circuit without interrupting the flow of current.The rheostat is consisted of ceramic core and a resistive wire wrapped to form a toroid coil with a wiper axle.