Standard Horizon SSM-21A Submersible Speaker Mic with Ear Jack Standard Horizon SSM-21A Submersible Speaker Mic with Ear Jack Standard Horizon SSM-21A Submersible Speaker Microphone with Heavy Duty Belt Clip. Rated Intrinsically Safe for use with the HX400IS SKUSTXSSM21A MAN#SSM-21A ID#: 6571 Our Price: $69.95 Availability: In Stock Shipping: FREE Ground Shipping! Condition: Brand New Add to cart We’re sorry for the inconvenience, but please know we are working hard to replenish stock and fill backorders. Global shipping constraints and other material shortages have slowed the supply of products in many industries, including GPS and Marine electronics. We update the Estimated Shipping Date on our website in real time, so feel free to check back frequently. Thank You for your patience and for shopping with The GPS Store, Inc.