The is a shaped like a flattened and deformed avocado.

The consists of four major components: the body, the rotating cam, a cover plate, and an actuating lever assembly.

The body and cover plate are forged from aluminum. Superficially, they are mirror images of each other, although there are some details where this symmetry breaks down. In other, more practical words, the front cover and rear body are roughly the same thickness, and the seam between the two splits the closed device in half. A 6.4 mm. stainless steel rivet joins the front and back near the top. Each piece has a cast stainless steel insert, and the inserts are shaped so that with the covers closed, the inserts form a groove for 10 mm. diameter rope.

The cam assembly pivots on a roughly 15 mm. stainless steel axle attached to the body. The attachment method is not clearly visible. A spring-loaded button protruding from the cam axle passes through a hole in the front plate when the cover is closed.

The bottom of the body and cover have aligned 18 mm. holes that form the attachment point. The body has a cast stainless steel anvil next to the hole. The anvil has a U-shaped groove for the rope to run over. The anvil and lever assembly are held by a 5 mm. stainless steel rivet.

The rotating cam is cast steel. It has a webbed design with several reinforcing ribs. The right side of the cam has a rounded V-shaped rope channel with about a 6 mm. minor diameter at the base of the V. The left side has two small grooves to provide a finger grip for feeding rope. The bottom of the cam has a flat area that squeezes the rope against the lower anvil when the cam rotates counter-clockwise (i.e., when it closes).

The lever assembly consists of a control lever connected to the cam by a steel link. Pulling the lever downward forces the link upward, opening the cam; however, once the lever passes a certain point, the link disengages and the cam rotates closed again under rope tension. At this point, raising the lever opens the cam; but again, the action stops if the lever moves too far.