It works as it is described ( even better ). I use it for a siren driver horn on full frequency. The result is amazing ! ! ! It is so powerfull. I measurered 95 dB with 4 A at home. In the car, with 60 A , gush.... Can't guess :)
The product was defective but they refunded the money within a few days without delay...as such I gave them 5 stars for their Customer Service quality.