Guns such as these were used in pre-colonial south-east Asia by merchant vessels, often to fend off pirates. This particular example was obtained by the vendor in the Philippines. It has a two-stage octagonal/round barrel and is decorated with vines and other foliage with a snake-like creature mounted on the top.
A hinged post for mounting the firearm on the ship’s gunwale also features. The breech end, say the auctioneers, appears to be filled with concrete.
It measures 2ft 6in (76cm) long, weighs 21.2lb and is estimated at $1500-2000.