For regular Hardie siding this is a good, durable gauge. However, I use the Hardie beaded siding and this proved to be a complete failure. The groove for the bead was just below where this applies pressure, so in tightening the clamp the gauge invarianly slid down. Additionally, it pulled quite far away at the top. I tried slipping a few pieces of flashing (three worked best) between the gauge and the siding, which helped, but it still was too inconsistent in staying put to rely on it.

Ultimately, I did return them. The construction is very sturdy and of high quality, and I really would have liked them to work. It would be good if the manufacturer mentioned these do not work well for beaded siding to save everyone the trouble of finding out for themselves.

I do have a set of the plastic version of this product, and being larger and applying pressure a little higher on the board work rather well. I just wanted a second set and thought these might be more durable too. My prefered method is to install one a quarter of the way from the far end of the board. I take a plywood gauge made with two pieces screwed together, with the larger one sticking up my exact reveal above the second. I shove it up against the previous row in the middle and mark at the top. I then place the far end in the Gecko Gauge and hold the end that abuts the previously installed piece and nail that off (always backing the joint with flashing). I then go to my middle mark and nail that off, reaching back to fill in, and then end on the section with the gauge (this way if the gauge slips even slightly I can catch the variation prior to nailing).

I'm a do it yourself homeowner who has decided to replace the siding on my house with 6.25" Hardi. Researched the tools I would need and these looked very necessary. I have been so impressed with these Gecko Gauges. It truly makes installing Hardi siding a one-man job whether you're nailing 12' planks or anything shorter. I use them for just about anything over a couple feet and in some cases I use just one.

They were easy to adjust to get my 5" reveal using 6.25" siding. They slip into place with ease and lock tight never damaging the siding. Just be sure you have the tool pushed all the way up to the rest point and the tool is fully vertical before locking into place. In the beginning I made a couple errors with these gauges but it was not their fault, it was mine. One hopefully learns from their mistakes.

I'm fairly early into my project but I don't see any weak points in these light weight but well-built Gecko Gauges. I think they will perform well for the entire siding job.

Installed Hardie fiber cement siding on my single car detached garage (using HZ5 clapboards), these gauges made it possible for me to do all of the work myself. Working from bottom to top, you simply slide these under the previous course of clapboards, lock them in place by raising the lever upwards, then sit the next course of siding in the notch in the gauges...it sets the reveal perfectly and holds them so you can nail down the clapboard.

There are a few tricks to using these. Do not try to raise the levers all the way up when locking these in place...halfway up is enough. If you're using HZ5 siding like I was (which has a beveled lower edge) , it's possible for the clapboard to slide out of the notch that's supposed to hold it in place...this happens if you tighten the lever too much, which causes the gauge to pull away from the wall. Just be mindful of this while working and you'll be fine.

I'm going to ding these 1 star on the review simply because with a few tweaks, the minor issues with these could be fixed to make them work flawlessly.

I've used both the Pac Tool Gecko Gauge as well as the SoloSider for installing LP Smartside on my two story Greek revival. I was so excited about the gecko guage, I loved the clamping action and the possibility of removing them and reinstalling them quickly. (the Solo Sider requires that you separate the center knob and reinstall to the correct orientation with each board) However, the gecko gauge allows the 3/8" siding to slide behind the gauge when in the clamped position. This requires that i stop what i'm doing, re-position the gauge, then re-position the siding.
I ordered the correct one for my application (my siding is 3/8 inch), but i still haven't had much luck.

The Solo Sider allows me to twist a knob for minor adjustments on the fly. Perfect for my out of plumb 107 year old home.

So I read the reviews before I bought these. I had read that people have had problems with these slipping down or opening up allowing the siding to wedge between the tool and the wall.
Got these a few weeks back and started using them lady week. All was going okay but I wondered why the manufacture didn't make these tighter.
So after a week of use the gauges wouldn't support a few 12 foot piece of 8inch hardie siding. No biggie, I have amazon prime. But first I figured I would call pac tools since I am not the first person to have this problem.
Well I along with many have bought the wrong gauge. These are made for 3/8 thick material. Hardie is 5/16th. I know, it's not much, but it matters. So I am going to double check the description on amazon and maybe send them a message about changing the description.
I am also going to put a scrap of denim between the cam and the rubber grippy part to make these clamp better.

Moral of the story. Don't buy this model for hardie siding. Buy the cheaper pair for 55$