Yamaha LP5A Pedal Unit For Portable Pianos; Black This unit is designed for use with the Yamaha P145 pianos and the official Yamaha L100B wooden stand (available separately). The combination of the pedal unit, wooden stand, and the Yamaha portable piano keyboard offers the most authentic grand piano playing experience from a low-cost instrument. Three Metal Pedals - Just Like An Acoustic Grand The LP5A provides three pedals which behave in the same way as an acoustic grand piano. The right pedal is known as the sustain pedal (also referred to as a "loud pedal" or damper pedal). The sustain pedal is the most commonly used in modern piano playing. When the sustain pedal is pressed, all notes played will continue to sound until the tone naturally ceases or until the pedal is released. The middle pedal is known as a sostenuto pedal. The function of a sostenuto pedal is similar to that of the right-hand pedal, but it only sustains only notes which are depressed at the time the pedal is depressed. The far left pedal is the soft pedal (sometimes known as the una corda pedal). This pedal softens the note and also modifies its tone quality. The effect is very subtle, but it results in a slightly softer, less powerful sound.