SM81 Speaker MicrophoneUniden&';s SM81 Marine VHF Speaker Microphone replaces Uniden&';s HHSPM.WARNING: This product can expose you to chemicals including LEAD which is known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov. Specifications: Type: Microphones Box Dimensions: 2"H x 4"W x 4"L WT: 0.32 lbs Quick Guide (pdf)