AD-400 — Starting selection brief Manufacturer: Boya Gongdao A specialist platform for long-distance inspection of flooded water tunnels, combining a tethered vehicle with project-specific sensing and tether management. Vehicle weight: 300 kg Depth rating: 1,000 m Official-site maximum range: 5 km Dimensions: 1,600 × 900 × 548 mm Forward camera: 4K Rear camera: 1080p Power: External tethered supply Configuration note: The official website states a maximum operation distance of 5 km; the supplied brochure lists 5.5 km. The deliverable range must be confirmed against the supplied version and project conditions. Confirm current specifications and delivered scope with the manufacturer before purchase.