Signal 21 Microphone Has Been Manufactured Using The Highest Quality Specifications To Be Water, Wind Dust & Impact Resistance. Small But Mighty. The Signal 21 Fits Perfectly Into The Palm Of Your Hand And Weighs Just 3.6 Ounces. With Features Includeing A Covered Audio Jack And Rotating Clothing Clip, This Is One Quality Shoulder Microphone No Officer Should Be Without. Compatible With Motorola And Kenwood Radios.