10 LED scale, up to 2000Wrms power measurements. 
Does not need a special power supply, because it is supplied directly from the speaker output. 
Ideal for car audio systems and PA systems. Also usable for bridged amplifiers. 
The unit can be used both horizontal and vertical. 
The kit comes with a front panel and four attractive front stickers, for the different scales. 
 
 Specifications 

four different scales: 
at 4 ohm load in low power mode: 0.3 to 400Wrms
at 4 ohm load in high power mode: 10 to 2000Wrms
at 8 ohm load in low power mode: 0.15 to 200Wrms
at 8 ohm load in high power mode: 5 to 1000Wrms
minimum input sensitivity: 1.1Vrms (low power mode)
maximum input voltage: 130Vpeak (high power mode)
current consumption: 25mA at full scale
luminous intensity: 8 to 20mcd / LED
dimensions: 120 x 40 x 28mm (4.7" x 1.6" x 1.1")  

▶ k4307.pdf