The P-125 is an 88-key digital piano with Graded Hammer Action. GHA imitates the feel of a grand piano. That means a heavier action at the bottom and a lighter action across the top. Apart from exciting piano sounds, the Yamaha P-125 has electric pianos, clavinet, strings, vibes and more. You can listen to it through its built-in speakers or headphones. You can also plug the P-125 digital piano into an amplifier.