Well, imo any exhaust muffler "barrel" is a straight thru, as long as it's inner piping is straight and allow for the air to flow straight out of the exhaust pipes, without using any bends or silencing passages like regular silencer type mufflers. And mostly the difference among branded ones and the ones wrapped with tin cans are the volume of the noise they make, when you get a cheap one it would be noisy, would be fun to attract attention but after sometime you would find it annoying, so tz better if you could find a recondition, decent branded one the first time, rather than buying both, like i did