Minelab Excalibur II Special Bundle with Headphones, Car Charger & Extra Rechargable Batteries Special Bundle with Free Minelab Headphones, Car Charger & Extra Rechargable Batteries RCB amplifies weak target signals inside the coil, reducing noise and boosting faint, deep objects High Visibility (Hi-Vis) fluorescent bodywork; NiMH Rechargeable battery pack for operation up to 12 hours Hi-Vis Skid plate; Side-mount shaft for shallow and surf-wading (available as an optional accessory) BBS multiple frequency technology (1.5kHz - 25.5kHz)