A double-chamber padlock wrought iron lock, essentially two lock mechanisms sandwiched inside one lock body. You have to fully rotate the key within the first chamber to unlock the first bolt, then rotate the key to a 3pm position and drop it into the back chamber to operate the second bolt. Possible makers marks on shackle. Lacking key.

3.625 x 4 x 1.125 in (9.21 x 10.2 x 2.9 cm)