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Description
Groundtech GR-4 Dual 3D Ground Scanner and Integrated Pulse Induction Metal DetectorTake your exploration to the absolute limit with the Groundtech GR 4 DUAL. This elite, hybrid system integrates an advanced 3D Ground Scanner with a high performance Pulse Induction metal detector, giving serious treasure hunters, archaeologists, and relic seekers two powerful technologies in a single, streamlined device. Whether you need to map out deep subterranean voids like tunnels and chambers up to 49 feet (15 meters) deep, or rapidly search and
Take your exploration to the absolute limit with the Groundtech GR-4 DUAL. This elite, hybrid system integrates an advanced 3D Ground Scanner with a high-performance Pulse Induction metal detector, giving serious treasure hunters, archaeologists, and relic seekers two powerful technologies in a single, streamlined device.
Whether you need to map out deep subterranean voids like tunnels and chambers up to 49 feet (15 meters) deep, or rapidly search and discriminate metals in the upper layers of soil using a heavy-duty pulse system, the GR-4 DUAL provides the ultimate all-in-one field solution.
Key Features
- Dual-System Hybrid Technology: Seamlessly switches between high-depth 3D Ground Scanning (Gradiometer) and a powerful 1 kHz Pulse Induction Metal Detector.
- Expanded 6-Scanning Mode System: Includes 3D Ground Scanning, Live Scanning, Pinpointer Function, Detector Fast Scanning, Detector Advanced Scanning, and 3D Ground Scanning Detector Mode.
- Advanced Metal Discrimination: The Detector Advanced Scan mode lets you tune detailed settings to filter out trash, locate deeper targets, and clearly distinguish between ferrous and non-ferrous metals (like gold, silver, and copper).
- Extreme Depth Capabilities: Scan up to 15 meters (approx. 49 feet) deep using the 3D imaging system, and detect targets up to 3 meters (approx. 10 feet) deep using the integrated Pulse Induction system.
- Standalone Field Operation: No external smartphones or tablets are required to start hunting. View all settings, active scanning modes, and real-time color targets directly on the built-in HD color display.
- Deep 3D & 4D Data Analysis: Connect wirelessly to the G-Portal mobile app (compatible with iOS and Android) to view highly detailed, color-coded graphic visualizations, isolate target shapes, and generate comprehensive survey reports.
Technical Specifications
- System Type: 3D Ground Scanner (Gradiometer) & Pulse Induction Metal Detector
- Sensor Technology: MFS-2 Dual Sensor Technology (± 2000 µT)
- Detector Technology: Pulse Induction Technology (1 kHz frequency)
- Maximum 3D Scan Depth: Up to 15 meters (approx. 49 feet)
- Maximum Detector Depth: Up to 3 meters (approx. 10 feet)
- CPU / Processor: Fast 240 MHz CPU with a 12-bit A/D converter
- Display: Integrated HD color screen for standalone field use
- Wireless Connectivity: Bluetooth 4.2 BLE
- 3D Analysis Software: G-Portal Application (Android & iOS 3D/4D Analysis Program)
- Battery Type: 3.7 V Li-ion rechargeable battery
- Operating Time: Up to 10 hours in 3D Scanning mode / Approx. 6 hours in Pulse Detector mode
- Charging Interface: Type-C input (supports 25W fast charging adapters)
- Operating Temperature: 0°C to 70°C (32°F to 158°F)
- Multi-Language Support: 11 languages on-device / 25 languages via the mobile app
- Warranty: 2-Year Manufacturer Warranty
What’s Included in the Box?
- Groundtech GR-4 DUAL Main Unit (with integrated HD color display)
- MFS-2 Dual Sensor Module
- PiD35 detector search coil
- Heavy-Duty Field Carrying Bag
- Type-C Fast Charging Adapter
- User Manual & Official Warranty Documentation
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.3 ★★★★★
Based on 14 reviews
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Product Reviews
★★★★★ 5
Can't go wrong with Acorn for as long as they last!
Size: 12-13 Women/10.5-11.5 Men, Color: Charcoal
Acorn is just a great company all around. I had bought my husband these slippers over 20 years ago. They are still in great shape although the sole has worn in some places. But nothing's coming apart! However, I decided to replace them for him. His foot is 10.5 and they are a little hard to get on right away-of course, after over 20 years of having "worn in" the original pair, anything would feel tight. So I'm not holding this against them. They will relax with use. The only difference is that the original sole was black and these are tan. I think I would prefer the black, but since it's only being worn in the house, no big deal.
My husband has really cold feet and these slippers never fail to warm his feet right up! He said they feel really soft to walk in and like the cushioning. They're not too heavy and fit him great! I have Acorn slippers myself that I've worn every single day in the house and outside to the mailbox too. They last.
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Reviewed in the United States on April 11, 2026
★★★★★ 4
Very warm.
Size: 13.5-14.5 Women/12-13 Men, Color: Navy Blue
Very warm and comfortable. A little difficult to put on with the collared top.
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Reviewed in the United States on January 19, 2026
★★★★★ 5
You won't be sorry
Size: 10.5-11.5 Women/9-10 Men, Color: Black
Great padding for comfort and terrific warmth. I bought a pair of Acorns 30 years ago and still have them. Updated to a new color and now feel the benefit of newer padding! I used the sizing listed for shoes and like the roominess for thicker sox. Well made and a joy to put on. (Wisconsin)
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Reviewed in the United States on December 25, 2025
★★★★★ 5
Great Slippers
Size: 12-13 Women/10.5-11.5 Men, Color: Charcoal
Comfy, great price, looks great, fits well, size aligned, great quality. Love these slippers.
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Reviewed in the United States on February 16, 2026
★★★★★ 5
Extremely comfortable, leather sole. Hard to find a style.
Size: 13.5-14.5 Women/12-13 Men, Color: Navy Blue, Size: 13.5-14.5 Women/12-13 Men, Color: Navy Blue
Totally worth the price. This type of style is very hard to find, my husband had another pair a few years ago that he was never able to replace. These fit his wide feet and are very comfortable. The elastic at the ankle is not too tight. So glad I was able to find him a replacement. We bought the blue in a size 12. Love the fact that they are washable.
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Reviewed in the United States on February 12, 2026