Nickel plating C Flute 16 closed holes E key split. Tube material: copper plating. Tone key system: bent / closed cell /E key. Surface treatment: Nickel plating. Please leave us all positive feedbacks and all “5 Star” ratings, we will do the same to you. Please do not leave us any negative or neutral feedbacks before contacting us to solve the problem. It won’t help you solve the problem any faster by leaving negative feedbacks. Your satisfaction is very important to us.