North American Arms (NAA) NAA-.22 Short Short 5RD .22 Short 1

The NAA .22 Short (limited production runs yearly) is the World’s
smallest and lightest five-shot Mini-Revolver. Like all NAA
Mini-Revolvers, they are covered by a lifetime warranty against defects
in material and workmanship.
As with every NAA Mini-Revolver, the hammer need not rest on an empty
chamber. Using the original half-way notch cylinder, the hammer may
rest safely and securely without chance of accidental discharge.  Please
see the owners manual for more information.
Specifications:

Weight: 4oz
Overall Length: 3 5/8″