The Susato Kildare whistles are constructed of high impact ABS plastic. They have a curved channel bezel and are made in two pieces for fine tuning adjustment. The interior is slightly tapered, which provides more power with less air pressure. They are distributed in 4 calibers according to the tessitura, from G sopranino (Very Small caliber: VS) to D tenor or low whistle (Large caliber: L).
These are the keys by gauge:
MP gauge (Very Small): G, F, E, Eb, D, in high range.
Caliber P (Small): Eb, D, C, in high range.
Caliber M (Medium): Bb, A, G in middle range.
G gauge (Large): F, E, Eb, D in low range.
The tones of the M and G gauges usually fall within what is called Low whistle, although this term is very imprecise.
