This is an Israeli 82 mm caliber anti-tank rocket launcher, patterned after the famous U.S. Bazooka launcher of World War II fame. It was operational in the 1970s and 1980s.
The U.S. Army Ordnance Museum transferred the object to the National Air and Space Museum in 1989.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.