Introduce yourself to SandLock. SandLock Sandbox believes every child can benefit from sand and water activities. They consider it a foundation for education teaching art literacy math science social studies technology and more. Kids never forget what they learn in a SandLock Sandbox. The SandLock Difference Interlocking: Precision design makes it easy to assemble and disassemble. Durable: Commercial grade solid plastic (HDPE) with UV stabilizers. Ground Barrier: Plastic panel keeps sand and ground material separate. Coverlock: Heavy-duty vinyl keeps sand clean dry and free of debris. New Ground Level Sandbox features precision engineering that provides durability with a stylistic design. Commercial grade UV Stabilized HDPE Plastic. Patented interlocking construction eliminates sand leak. Quick assembly and can be secured to any surface. Puncture resistant ground barrier keeps sand and ground materials separate. Comfortable removable seating that doubles in lifting cover to create water run-off. CoverLock System and versatile umbrella bracket for quick shade adjustment. 5000 lbs Sand Capacity.