Mine has been one of my trusted Old School Zed Audio White Mean Machine 99s with the 1 and 2 ohm switch on it. Ive used it in just about every vehicle Ive had a system in. Ive used it in Stereo mode from 4 ohm to 1 ohm applications, on subs from 4 ohm to 2 ohm, and I have even ran it in Stereo and Mixed Mono. Its old , but still works very nice and Ive never had to have it repaired since I bought brand new back in the day. It still looks fairly presentable today with a few battle scars on her and still works very well. Thanks Steve Mantz for making a dammned good amplifier!!