F-C EXTRA-SELECT STRAIGHT COW ELK FLANK - Selected and processed for us. It's my favorite for our F-C Flat-Wing (no-hackle) caddis PLUS Troth Elk Hair Caddis in sizes 12 thru 18 on TROTH DAIICHI 1310 caddis dry-fly hooks. I only tye the Flat-Wing in sizes 14 and 16. COLORS: (1)Natural, (2)Bleached, (3)Black, (4)Olive, (5)Dun, (6)Red, (7)Yellow. This cow-elk "flank-hair" is more hollow (floats better) than bull elk. Nice piece.