To really needle felt you needle the diversity of all these needles!!
The set comes with a storage box and:
20 Triangular Needles.
Triangular needles are the most common felting needles with three sides and the are great for all kinds of felting!
Black 42 Gauge is (XS) very fine is for sculpting and finishing.
Red is 40 Gauge (Small) that is best for details.
Green 38 Gauge (Medium) is for working and shaping.
Gold 36 Gauge (Large) is for starting with core wool and shaping.