The seller had these 2 pieces on sale at the same time. Both were Terengganu, and from the same period. While I think they were not made at the exact same time, they were probably owned by the same person, who probably had worn them as a pair.
The black bands are horn. Apart from Terengganu, Sumatra also had keris sheaths of similar aesthetics. I have a keris panjang with such alternating black and white batang, and that keris was probably 19th century.
Yep, I'm going to be in black.
Makes the white stand out.