Hey swimmers and athletes! This Keenso swim training belt is seriously awesome for building up your swimming strength and endurance. The 4-meter length gives you plenty of resistance whether you're working on your freestyle, backstroke, butterfly, or just kick training. Made from high-grade latex and neoprene that's seriously durable - this thing won't break, tear, or wear out like those cheap plastic or fake leather belts. The adjustable waist band fits waists from 56-100cm (that's about 1.84 to 3.28 feet for us non-metric folks), so it works for pretty much everyone from teens to adults. I love that it's lightweight and easy to carry to the pool - just toss it in your gym bag and you're good to go. The elasticity is perfect - enough resistance to really challenge you but still comfortable to wear. It's like having your own personal swim coach right there in the pool with you! Whether you're training for competition or just want to improve your swimming fitness, this belt makes every lap count. The 4mm thickness (in the B size option) provides solid resistance without being overwhelming. Seriously, if you're tired of swimming endless laps without seeing improvement, this resistance belt will take your training to the next level. Plus, the company stands behind their product with solid customer service - they promise to solve any issues within 24 hours. Perfect for home pools, gym pools, or wherever you do your swim training. One of those simple but effective training tools that actually delivers results!