20pcs IRFZ44N IRFZ44 N-Channel MOSFET Transistor, International Rectifier Power 49 A 55 V,3-Pin

Worked as expected. Wired up 12v fan powered from battery and controlled from Arduino Pro Mini(3.3v). I got what I needed at a great price.

Look at the numbers carefully these are not logic level devices and will not work directly with most micro controllers. The one I needed was IRLZ44N, very close part number... Explains why my project failed.

These work pretty fantastic with 3.3v logic or 5v logic. Great little mosfet with high amp rating.

All working! Although the packaging was slightly lacking in protection. I made a test rig and tested them after straightening a few legs and they are all good, so I'm happy with that.

I think that's a quality thing where the "off state" would be closer to 0 if it was more expensive but considering they're like 50cents each I guess it's alright. Also thresholds probably I just don't know enough regarding the data sheet to explain the values I got. It took me a bit to figure out how to wire these things as it's almost backwards to me how they work. But I am using it as an on/off power switch for a sensor that is fed by a ~5V source. So my microcontroller pin that's connected to the gate outputs a high of ~3.3V and then the drain is connected to my sensor's ground, source is the 5V ground. In my case "on" was 5.26V and then the off state was 0.5 or so takes a little bit of time to get there i.e. not immediate but yeah. So I think this works, I was aiming for an "absolutely off" deal but I can look into that more. As my case is a battery powered device.

They are what they say they are, and cheap. I accidentally bought 2 of these kits but it's a common enough mosfet to use everywhere. I have only tested them on 5v logic but i assume 3v3 won't be an issue

I do a lot of Arduino work and for driving higher current loads, these are the best. Was good value for 20pcs set, but I would like to see them get a bit less expensive.

Be aware that even though the gate threshold is listed as 2-4 V, this is NOT a logic-level MOSFET, and it will burn up with a high load without using a higher voltage on the gate. If you need something to use directly on a microcontroller, get something that starts with "IRL" (not IRF)