The material of clarinet is generally wooden and glial. Advanced clarinet are made of ebony, very beautiful. This wooden is very afraid of temperature changes, to avoid light and humidity. If wet ordinary plastic gum, it is not so delicate, each time blowing, to clean up the tube body saliva, often wipe the keys on the tube body, to avoid the production of green. The selected clarinet mainly looks at several aspects :(1) whether the appearance is bright, whether there is scratch, whether the key gloss is symmetrical ;(2) whether the sections are tightly connected after assembly ;(3) whether the keys are completely closed and there is no gap ;(4) whether the keys are soft and no noise ;(5) whether the key screws are loose ;(6) whether the items in the instrument box conform to the items on the manual (usually there are boxes, one or two whistles, whistle cards, flute head cover, and some black pipe distribution interface cork paste in addition to the instrument itself).