These headphones have been tested and still work great. 

Technical Specifications:

• Single rotary volume control with “stay put” segmented “click” positioning.
• Selector switch for metal detector compatibility with all single-output metal detectors without adapters.
• Heavy-duty muff-to-muff connection cable.
• Heavy-duty 48″ coil cable with special 1/4″, 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… no screws, no wire frame, no rust!
• Speakers designed for maximum sensitivity, efficiency, durability, and signal quality.
• Special sound-blocking muff design eliminating environmental ambient noise up to 24 decibels.
• Impedance: 150 ohms nominal.