Merkur’s 510 Progress Adjustable Long Handle double edge razor is the first of a new pedigree of performance enhancing safety razors with adjustable heads. Turning the knob at the base of the handle creates either a narrower or wider gap between the blade and the safety bar. The blade position preferred can be noted by using the 1-5 scale around the bottom of the handle. The head of the Progress Long Handle measures 1-5/8" long x 1" wide. The handle is 4-3/4" long x 7/16" diameter, and has a secure-grip rib design. Overall length of the Progress is 5-1/8", and it weighs approximately 3.4 ounces. The knob at the base of the handle of this two-piece razor with long-screw mounting is turned clockwise to unscrew the top plate for loading the blade. Uses any double edge blade. Blades are not included with razor so remember to order them. Boxed. $79.00