Oasis Value-Sets include genuine Oasis All-Weather Water Bottles and Basic Hold-Guards paired for a perfect fit. All-Weather Bottles feature sturdy natural polyethylene construction with a silk-screened design. The Hold-Guard is sturdy metal with non-toxic powder coating. The guard hangs inside the pet s cage and protects water bottle and cap from chewing biting and gnawing damage. The easy to adjust hanger strap fits many sizes of aquarium-type pet environments (hangs over the upper edge) or wire cages (hanger straps slides through the wird side.) Suitable for fancy mice fancy rats gerbils hamsters sugar gliders and hedgehogs. 8 ounce All-Weather Bottle with matching Hold-Guard.