only one c. 1900's original american antique interior residential sliding or pocket door mortise lock fabricated by the russell & erwin mfg. co., new britain, ct. the mortise lock was used with a sliding door, with the "male" lock containing a "finger" lock (actuated by turning a key) and the "female" containing the catch or opening to secure two doors together. the push button releases the handle used to pull the doors from their pockets. the original recessed handle backplate was already removed and/or missing. the face plate has a nicely aged surface patina. the baked black enameled cast iron lock box is in good shape. measures approximately 1 x 3 1/2 x 7 inches.