Picture shows both an uncut length and a pre-cut piece. Pre-cut piece has an overall length of about 3.25 inches.

Used to hold bra straps in place. Picture shows 1 unit in unsnapped position.

Used to hold bra straps in place. Picture shows 1 unit in snapped position. Distance from center of spring to center of stud is 45mm (about 1-13/16inches) but unit length is usually about 3-1/2inches depending on how close one trims to the snap edges.