This is such a cool fly box - super lightweight (entirely made of foam), magnets hold it closed, and the graphic of the rainbow trout on the cover is killer. the fly box will hold over 300 small nymphs. This slim profile box is not a good choice for dry flies like salmonflies or grasshoppers - their profiles are too large. It is an ideal box for Euro-nymphs and other bead head or non-bead head nymph patterns that are smallish - size 12, 14, 16, 18, 20.