Code Red Signal 21 Microphone . 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. Package Contents: Code Red Signal 21-m4 Microphone The Code Red Signal 21-m4 Microphone is a quality addition to the Code Red lineup. For more great deals on Travel Accessories by Code Red please browse our Code Red Travel Accessories page.