The I20 is a standard 16Ohm extension speaker, boxed in an ABS housing.
Tamper protection is provided via microswitch to detect removal from the fitting surface or removal of the lid.
The speaker itself is of mylar construction and provides 92dB of sound output (at 1 metre distance).
Designed to operate at 10-15VDC.
Also available dual tone – use part code I40.
16 Ohm Tampered Extension Speaker