This is the OTB Boots ABYSS. It features a drainage design for amphibious landing missions and is compatible with diving fins such as the Scubapro Jet Fin. The boots have only been worn once and are in excellent condition. The size is 29cm, but the width is narrow, so they would fit best for someone who wears 28.0-28.5cm. Below is information from the official website: Product Information: ABYSS Navy SEALs Approved: Designed with a superior drainage structure for optimal performance in wet environments. Tested and approved by the world's elite special forces (SOF) personnel. Best Uses: On-the-water, diving, and beach-over (OTB) missions. The Abyss is compatible with military swim fins. Features: GRIP-STIK-WET outsole for multi-traction on wet surfaces. Features a field-tested serrated heel design that provides excellent traction on ladder rungs. Field-tested GRIP-STIK-WET climbing rubber rand with strategically placed drainage ports provides traction and protection. Future Foam EVA cushioning with a full-length polypropylene shank provides rigidity and support when climbing ladders. Waterproof EVA footbed with a drainage port system is designed for easy drainage. Performance Upper System: Weight per foot (based on size 10): 1.2 lbs Moisture-wicking and water-friendly sock-like design. Features a sand-tight collar, preventing particles from entering during beach operations. Easy on and off with heel and front webbing pulls Operational-tested flat, non-binding lacing system for long-distance swimming Optimized design for use with most standard diving fins. US Military Authentic Marine Corps Amphibious Rapid Deployment Brigade marine recon Navy seals bates New Balance Danner