EUROCOPTER
For example;
0 means single eng, 5 means twin
Middle number=weight
120... 2 tones, 0 - single eng
130... 3 tones, 0 - single eng
135 ... 3 tones, 5 - twin engines
145... 4 tones, 5-twin eng
155... 5 t, twin eng
225... 20 tones, 5-= two eng...
btw. sorry if I was off-topic