Sun Ray In line Target Probes are designed to work with your metal detector, through the headphones you are using or the existing speaker (if you do not use headphones). Powerful and easy to set up and use, the Sun ray probe uses the same discrimination pattern you have set for you detector and sounds like your detector. No need to disconnect, just flip the easily accessible switch and your probe is on, or off.
Invader™ GI-1 Target Probe for all GTI, icluding 1500, 2000, 2500
Invader™ YF-1 Target Probe for Ace 150 & 250, GTP1350 and GTAX 550, 750 & 1250 - read exception