Material: Metal. Rubber rings are dismountable, durable and long service life.Exercise lip muscle endurance.Practice mouth strength and fix mouth shape.Use both ends, pull one end, exercise lip biting force and lip muscle strength concentration.One is like holding a pencil for 10-20 seconds at a time.Applicable for Trumpet Trombones Cornet Clarinet Saxophone Horns.This trumpet mouth exerciser, according to the principle of trumpet mouth and breath forward, lip concentration and mouth closing, avoids pulling out the corners of the lips and lips, practices gums, teeth close, teeth alignment, lips parallel, while vigorously practicing, corrects the mouth shape and breath.It is recommended that you should not use the immediately before playing, as the exercise will leave you tired.Specification:Material: Stainless steelColor: Silver/GoldItem size: 65 * 18* 10mm / 2.6 * 0.7 * 0.4inPackage weight: 38g / 1.4ouncePackage Includes:1 * Mouth Strength Trainer