Abstract: A night vision device has an objective lens mounted on a housing, and arranged for receiving light from ambient into the housing. An image intensifier and an eyepiece lens are also mounted on the housing. An adjustable iris defining an iris opening is mounted on the housing on an end of the housing generally opposite to where the objective lens is mounted. A sensor for detecting light intensity is connected to the housing and located toward the second end of the housing. The sensor controls the size of an area of the iris opening in response to the light intensity detected for keeping the area of the iris small so as to maintain a depth of field of the night vision device.

Abstract: A compact, portable sled for transporting a person comprises a flexible panel, sheet portions and strapping. The flexible panel has head and foot portions, first and second sides, a sled length, and a sled width. The flexible panel is constructed of a wear resistant material for dragging over rough terrain. The sheet portions made of limp material that is less resistant to wear than the flexible panel. One sheet portion is attached to and extends laterally outward from the first side of the flexible panel. Another sheet portion is attached to and extends laterally outward from the second side of the flexible panel. The flexible panel and sheet portions are collapsible to a compact configuration and expandable from the compact configuration to a use configuration in which the person may be received on the sled for transporting. The strapping is used to secure the person in the sled.

Abstract: A compact, portable sled for transporting a person comprises a flexible panel, sheet portions and strapping. The flexible panel has head and foot portions, first and second sides, a sled length, and a sled width. The flexible panel is constructed of a wear resistant material for dragging over rough terrain. The sheet portions made of limp material that is less resistant to wear than the flexible panel. One sheet portion is attached to and extends laterally outward from the first side of the flexible panel. Another sheet portion is attached to and extends laterally outward from the second side of the flexible panel. The flexible panel and sheet portions are collapsible to a compact configuration and expandable from the compact configuration to a use configuration in which the person may be received on the sled for transporting. The strapping is used to secure the person in the sled.