A trimmer or preset is a miniature adjustable electrical component. Trimmers can be variable resistors (potentiometers), variable capacitors, and trimmable inductors. They are common in precision circuitry like A/V components, and may need to be adjusted when the equipment is serviced. Unlike many other variable controls, trimmers are mounted directly on circuit boards, turned with a small screwdriver and rated for many fewer adjustments over their lifetime. Trimmers like trimmable inductors and trimmable capacitors are usually found in superhetrodyne radio and television receivers, in the Intermediate frequency, oscillator and RF circuits. They are adjusted into the right position during the alignment procedure of the receiver. Trimmers come in a variety of sizes and levels of precision; for example, multi-turn trim potentiometers exist, in which it takes several turns of the adjustment screw to reach the end value, allowing for very high degrees of accuracy.