The unit worked perfectly for stepping down 12vdc to 9vdc. As another reviewer mentioned, by convention, the color red for wiring should be reserved for 5vdc. They used red for the 12vdc input and yellow for the 9vdc output.

Worked as intended.

I needed to step down the voltage for some lights in my rv. Worked great. Keeps them from blowing.

Works as expected. I used it to bypass the zener diode on a Honda CBR F4i (that steps from 12v down to 9v). Unfortunately this didn't solve my problem as I have a lithium ion battery that was keeping the voltage north of 13v with the bike off so it stepped down to 9.something which is slightly higher than the Honda ECM allowed 7-9v range. Probably not an issue with a factory lead-acid battery and certainly not an issue with this product (just some info for those attempting the same thing).
I would purchase again.

Plastic. Worked well though so far.

Product is rated for 12v input with 9v output. The item I received only puts out 3.1v. I cannot use it for my use case.

I recently gained a 1998 Kawasaki Ninja 600 zxr,, for the life of me could not figure out what was wrong with it and why it would not run.. finally a friend of mine told me check the voltage going from the ignition to the CPU,, it was 12 volts.. he then informed me that it's only supposed to be 9 volts after I purchased and inserted the bike started right up.. a bad review for the ignition system I bought here but a good review for this easy remedy

this little guy is great ! used to power 6 amp mini computer