These are one pound bags of Dentalium vernedei shell. The shells are approximately 0.75" to 2" long.
The pieces are a mix of shells with some as short as 0.75" and some up to 2". Please note, there may be some broken shells that are going to be smaller, perhaps, as little as 0.25" or 0.5" as well as a few shells that are longer than 2".
Each bag will vary to some degree. You will not receive the exact bag from the photos but something very similar.
The shells are smooth.
A USFWS export permit is required for all shipments outside the USA.