The DetectorPro Jolly Roger Ultimate metal detector headphones boasts extra features like Dual Volume controls and a Limiter Switch that reduces the volume of excessively loud signals. A special limiter circuit gives you a smooth reduction at excess volume levels and can be disabled with the click of a toggle. Dual-rotary volume control with "stay put" segmented "click" positioning. Limiter Switch for reduction of excessively loud target signals. Selector switch for metal detector compatibility with all single-output metal detectors without adapters. Heavy-duty muff-to-muff connection cable. Heavy-duty coil cable with special 1/4-in 90-degree angle stereo connector. Compact carry and storage foldable design. Heavy-duty polymer muffs with full-ear surround soft comfortable cushions. Adjustable padded headband. Speakers designed for maximum sensitivity efficiency durability and signal quality. Special sound-blocking muff design eliminating environmental ambient noise up to 20 decibels. Frequency Response: 150 Hz - 20 kHz. Impedance: 16 ohms nominal.