A very high quality external speaker that comes with a steel clip on the back to attach to your harness or belt. Can be used with enhancers to give a better signal with the SD, GP and GPX 4000. Minelab GPX 4500 and GPX 5000 have an inbuilt amplifier so this speaker can be plugged directly into the battery. 1/4″ (6.5 mm) jack and measures 73x65x30mm. Great for the Summer when it is too hot to wear headphones!