Autotek mean machine M2000.4 That is the model I was looking at . Online it claims that This amp does 125rms x 4 x 4ohms . Should I buy it ?
Since Autotek is not a CEA-2006 electronic standards compliant manufacturer I would not trust those numbers. With only two 25 amp fuses, its maximum output at 13.8 volts (typical alternator output) won't exceed 690 watts peak power for all four channels, so I wouldn't expect it to produce more than 80 watts rms per channel, and at a very high amount of distortion at that. If you need a good 4 channel amp that puts out a solid 125w rms per channel then you need something like the Polk Audio PA D4000.4. However, it would be better if you told us what speakers (brand & model) you need to power.
It's like a lot of budget brands. It's ok, but it's not what's advertised. It claims to be 1000w rms. It's probably 500-600.
It's like a ford escort. It'll get you where you're going, just don't expect to win any races.
Figure on something around 100×4 at 4 ohms per channel, and probably 125×4 at 2 ohms or 250×2 bridged. Maybe slightly more powerful than that, but not much.
The reviews on the Autotek mean machine M2000.4 are quite mixed.
Too many folks were not pleased. Plus, Autotek has discontinued this model. That should tell you the whole story right there.