Strong, durable storage boxes are designed for frequent access and maximum stackability. Maximum security box with string-and-button closure keeps your check-size files secure, even if box is overturned. Reinforced plastic handle makes it easy to pull box off shelving. Storage boxes offer easy one-step FastFold setup. Stacking weight is 500 lb.Strong, durable storage boxes are designed for frequent access and maximum stackability. Maximum security box with string-and-button closure keeps your check-size files secure, even if box is overturned. Reinforced plastic handle makes it easy to pull box off shelving. Storage boxes offer easy one-step FastFold setup. Stacking weight is 500 lb.