These beautiful, unique seed necklaces are made by Batwa villagers using seeds of the flame tree (Scientific name: Erythrina abyssinica).
 
Necklaces come in a variety of lengths, but the extra-long can be wrapped around the neck 3 times on a typical adult, and the long can be wrapped twice. The mediums can be wrapped around on a smaller person, or child. They look GREAT layered!  
 
Sold separately are red-and-gray and all-gray necklaces that have both flame tree seeds and Job's tears, which were traditionally worn by Batwa criss-crossed across their chests: https://www.redemptionsongfoundation.org/product-page/jobs-tears-batwa-seed-necklace