I ordered 4 of these tilt brackets for installation of four 170W Rich Solar panels on my RV. Of the 4 kits, one kit was missing the bag of hardware (nuts, bolts, screws). Amazon fixed it easily, taking the return and shipping a replacement immediately. This kit is for solar panels up to 28" wide, and my 170W panels are about 26.5", so even though the listing says they are for less than 100W panels, I don't see any reason why you can't use these for a 170W panel. First, I should say that these are by far the cheapest option out there - thanks Renogy! Other similar tilt kits run 2x to 3x as much as this Renogy kit, and many are only for smaller panels. But what's the catch? There's no catch. This ki is sturdy, well-made, all aluminum, solid hardware, and plenty big even for larger solar panels. Actually, I priced out a DIY alternative, buying the angle bars and hardware from the home improvement store, and similar M8 knobs on Amazon, but it still cost over $180 for 4 sets! The price of this Renogy kit is simply unbeatable. A DIY kit would be somewhat different. The homestores sell them in 1/16 or 1/8 thickness, but the Renogy kit is 3/32. I found the 1/16 as probably too thin, and the 1/8 was probably thicker than it needed to be. I think Renogy's 3/32 is the right thickness for this application. They have 1.5"x1.5" but no 2"x1" as with this kit. Then, you have to cut and drill everything which would take 1-2 days. While I think this kit is a great deal and well-made, it does have some shortcomings. First, the thread on the knobs is too long, and it takes forever to thread them on. Next, is those damn wingnuts. What were they thinking? The knob and wingnut require two hands to install, along with two types of washers to keep track of. Tilting quickly becomes a real chore. With 4 panels and 24 knobs to take off and put on, tilting your panels can easily take an hour. Ugh! I did some upgrades to work around these issues. First, I ditched the wingnuts, and got a 50-pack of aluminum rivnuts. Then I set them on all prop bars, and on the two ends of the upper bars. Next, I trimmed the threads on each knob with a hacksaw, to about half length so that it goes into the ruvnut but no further. Now, installing knobs is a one-handed quick job. Next problem: the bottom bars are long, and if your roof is curved, they won't sit flat. To get around this, I cut one bar into 6 shorter pieces about 4.5" each, with a mount on each end, and one in the middle. You need a middle mount to position the panel almost vertically in the winter. One other shortcoming of the design, is that there is no easy way to stow the prop bars on the mount. After removing two knobs and laying the panels flat, you can screw the knob and prop-bar into one of the lower holes, but if you have wingnuts, you need to reach behind with one hand to hold the bar and wingnut, which is tricky, because the panel is only 3 inches above the roof surface. Doing this 16 times would be old really fast. So you have to screw 8 knobs into 8 bars, bundle them up, and carry them down the ladder, and store them inside. Dangerous and inconvenient. A better design would allow you to easily stow the panel, and turn a screw to stow the extra hardware until you need to raise them again. To get around this, one customization would be to stow the prop-bar attached to the middle bracket, but that wouldn't work, because the upper bar runs the full width of the panel so you can't put it down flat if there is any hardware attached to any of the holes. This is another bad design choice. To get around this, you can cut a notch in the upper bar in the middle, sacrificing one upper hole, but also weakening it. Not ideal, but it would help to streamline the process. And with 4 panels, 8 props and 24 knobs, 24 wingnuts plus 48 washers to deal with, tilting the panels is anything but easy. You'll quickly learn to hate it, never tilt them up, an regret the time trouble and money you spent to get this tilting capability. This mount kit is not do much 'designed' as it is assembled from stock parts. This is the crux of its weakness. And if Renogy went with rivnuts instead of wingnuts, that would require them to manufacture it, rather than assembling it from off the shelf parts. Price might go up a bit, but usability would skyrocket. Let's say it is a good starting-point: a kit that cost less than the raw materials, with a few good features, but ultimately requires a good bit of customization to turn this kit into something you can easily live with.
