JBtekBreadboard Power Supply Module 3.3V/5V for Arduino Board Solderless Breadboard

I was a bit hesitant at first to try these out on an existing project, so I put it on a blank board with my multimeter. Sure enough, it puts out a steady +5V and +3.3V depending on the jumper configuration at the top. For the record, I used USB power off a laptop.As someone else stated, these are compatible only with the newer solderless breadboards out there, such as the  Elegoo 3pcs MB-102 Breadboard 830 Point Solderless Prototype PCB Board Kit for Arduino Proto Shield Distribution Connecting Blocks . If you have an older style breadboard with wider distribution gaps between power rails and the board, this will not fit.It does tend to eat up space on the end when mounted properly, so you will lose the ability to use some of the board tie-in points. Thankfully it's not so big as to cover more than 5 or so rows. Also, be extra careful that you mount it on the rails with the correct polarities. If you're following the power rail guidelines for positive and negative, that means there's only one particular end of the breadboard they can go on to match (assuming you're using an MB-102 board). Elegoo 3pcs MB-102 Breadboard 830 Point Solderless Prototype PCB Board Kit for Arduino Proto Shield Distribution Connecting Blocks

I have purchased two of these units. Both units only deliver 2.6v when the jumpers are set to 5vthe 3.3v is coming in at 3.5vI returned the first unit thinking I got a bad one. I purchased another unit and I get the same think.I'm out on this one. Failed x2

no voltage protection, if you accidentally short this it will dereglate and give you 12 v rails forever on the 5v line . I think the converter chip they use is the culprit.

On a light load I lost the 5V regulator. It went up in smoke and the board never worked. I have been working with circuits a long time and never seen anything like it. This device needs a little extra circuitry to make it useful.

This unit works but make sure whatever you plug into it has a wide range of tolerance. The 5v rail showed 8v on my multimeter and the 3.3v rail was a little over 5v.