UniKeep case binders offer a fully enclosed way to bind and store documents. They are made 100% of polypropylene, including the rings, making them extremely durable, eco-friendly and safe for cleanrooms and county jails. These all plastic binders are the perfect blend between a storage box and a ring binder, offering encased protection from water and dust. The plastic rings are flexible and snap together without pinching or misaligning. The all poly design means they will never rust, while the slim look makes them easy to store and transport. Available in different sheet sizes, including letter size, half size or legal size, as well as several ring sizes in either black, white or clear. Some even feature a clear overlay wrap-around pocket on the outside, allowing you to customize and display a cover sheet.