Minelab 9" Concentric Waterproof Search Coil for X-TERRA Detectors, 18.75 kHz

This high frequency (18.75 kHz) lightweight waterproof Concentric coil has similar properties as the 7.5 kHz version, but is more sensitive to smaller, low conductive targets such as when detecting for jewellery on ocean beaches.

X-TERRA Series Coils
X-TERRA detectors are capable of operating at one of three different frequencies; 3 kHz, 7.5 kHz or 18.75 kHz. The operating frequency is determined by the coil being used and affects the detector's performance. Generally, the lower the frequency, the deeper the detector can penetrate the ground.
At low frequencies sensitivity to small low conductive targets is reduced. The higher the frequency, the higher the sensitivity to small targets, however detection depth is reduced.

Operate the detector at 18.75 kHz (high frequency) to find small nuggets and fine jewellery. Operate the detector at 3 kHz or 7.5 kHz (lower frequencies) when searching for coins and relics.