Yaesu MH-73A4B speaker microphone keeps up with the rugged capability of your VX-170 or VX-7. It features a 680 ohm electret condenser mic element and an 4 ohm speaker. Rated output is 0.5 watts. It is rated submersible to the IPX7 Standard (1 meter for 30 minutes). There is a revolving belt clip on the back of the mic. Size: 2.4 x 3.3 x 1.5 inches 5.3 ounces. This model replaced the CMP-460A.