Neohm brand (Made in Italy). Composition element control designed for applications where bushingless controls are required. Phenolic shaft insures insulation if control is used on a hot chassis. Pot can be adjusted from the top by screwdriver (or knob on 1/4 knurled shaft) or from the bottom of the chassis.
Great for antique radios. 24mm body, 1/4” shaft diameter. 500K linear. Twist tab mount.