From Celestion:
The G12M Greenback has evolved over the decades but still retains its essential, sought- after tone.Angus Young has been a Greenback devotee since the early days of AC/DC. This model is voiced with additional broad mid-range attack and restrained top-end to give a forward, punchy attitude to chords and a searing lead tone without fizz. With its well-controlled low end it can be used singly in low-powered amps, or in multiples for high-power rock heads. It’s an ideal guitar speaker to bring drive and definition to modern high gain amps.
Nominal Diameter: 12″, 305mm
Power Rating: 25Wrms
Nominal Impedance: Available 8Ω or 16Ω
Sensitivity: 98dB
Chassis Type: Pressed steel
Voice Coil Diameter: 1.75″, 44.5mm
Voice Coil Material: Round copper
Magnet Type: Ceramic
Magnet Weight: 35oz, 0.99kg
Frequency Range: 75-5000Hz
Resonance Frequency, Fs: 75Hz
DC Resistance, Re: Available 6.7Ω or 13.1Ω