Rock tumbling enthusiasts, this extra large 3.5-pound capacity barrel will take your hobby to the next level! The generous 5x6 inch size means you can tumble bigger batches of rocks, minerals, and gemstones, saving you time and effort. Made from high-quality rubber material, this barrel is built to last through many tumbling cycles. The leak-proof lid ensures no messy spills or lost grit during the tumbling process. It's specifically designed to fit the KoolStone Professional Rock Tumbler perfectly, though do check your tumbler's axle spacing before ordering to ensure compatibility. The rubber construction isn't just durable - it also helps reduce noise significantly compared to hard plastic barrels, which your family will definitely appreciate. The unique design promotes more efficient tumbling, giving you better, more consistent polishing results in less time. Whether you're a serious rockhound or just getting started with the hobby, this larger capacity barrel means you can process more material with each batch. No more waiting forever to build up a decent collection of polished stones!