Small type: there are two types of trumpet: vertical key trumpet (piston is the upper and lower movement trumpet) and flat key trumpet (piston is the rotating trumpet), which is the most widely used. The trumpet is composed of three parts: horn mouth, tube body and machinery. Pipe length 1.355 m (drop B adjustment), the mechanical part is composed of piston and piston sleeve, by pressing the piston to connect the bypass pipe to achieve the purpose of extending the pipe. Piston is divided into straight-lift type and rotary type. The trumpet consists of a horn mouth, a whistle tube, three piston tubes connected with three keys, a right finger hook, a bell mouth, a tuning tube, a water gate, a left hand tuning ring, a first tuning tube, a second tuning tube, and a third tuning tube. Generally used materials are: brass, copper, gold copper (gold brass), phosphorus copper pipe or titanium steel.