Excerpt from Stone's:

"PIHA-KAETTA
The Sinhalese knife. These knives are rather rough, heavy blades from half an inch to two inches wide and from five to eight long. They are usually decorated with a panel near the back and close to the hilt. These panels are either inlaid with silver, brass, or both; or deeply engraved and covered with thin plates of silver pressed into the hollows of the engraving. the hilts are decorated with chased silver or brass. Sometimes they are made of silver or crystal. the scabbards are made of wood, usually fluted, and often covered with silver. Frequently a stylus is carried in the sheath with the knife."