Professional Alto flute key of D , made of natural Macassar Ebo ny wood , treated with a special resin and not afraid of moisture - guaranteed ! 6 holes +1 for tuning .Two octaves and more . Lip plate corresponds to standard classical Alto flute . Lip plate as well are made of Macassar Ebo ny wood, in the center fix the brass oval ring for blowing. All holes are oval and the same size , that allows to get the same height sound for all notes. Brass rings on 3 hole - this is my Innovation ! This allows to bring the hole closer to each other on 1 centimeter for comfort fingers and does not affect absolutely on the sound quality. Plastic cork (not afraid of water) and fixed in the correct position for this key . Hz - 440 . lowest note D first octave . Can ask questions. Have a video on YouTube: youtube.com/watch?v=dYEzkeEoJCo