Have a very nice black and silver Ruger Mark I made in the 1960s. It is .22 LR caliber, barrel length is 6 7/8", steel frame, composite grips w/black Eagle, has the rear adjustable target sights with a heavy tapered barrel. This specific Ruger is known as the Target Model, used often in target shooting sports. The Mark I is known for it's accuracy and reliability; it's distinctive design resembles the German P08.