This  material is  a single feather barb from the lead edge of a primary wing feather from a large bird (turkey, goose, ducks, eagle, etc )

In general, goose biots are the most used by tiers simply due to the fact that they are relatively easy to find, cheap and a good size for most nymph patterns. Turkey biots are the next major type of biot available, and they are relatively larger and stiffer than goose biots, even though both birds are very similar in size