Gives me the option to use any 3 filters I want. Less expensive than other options and quality seems good. The mounting bracket is pretty heavy steel so you know It's solid. The pressure relief valve is nice, my only improving would be a pressure Guage to monitor pressure drop.Well built filter set and mount aside from the plastic threads. Brass lined would've been nice additionI considered using the 10" filters because they would be lighter when changing. These 20" beasts are HEAVY when full of water. But, these 20 inchers flow well and don't require changing as often. Just be ready to put some muscle in to it when you unscrew that final thread! I installed my system 9 months ago in a two person home and just changed the filters out of curiosity. My gauge showed there still wasn't any significant pressure drop... And, the filters looked like they could go longer, corroborating the gauge findings. This is Trinity aquifer well water in Kerrville, Texas. I used a 200u spin down, a 50u pleated, and a 5u wound string filter. Works fabulous ahead of the water softener. And I use the rust remover softener salt along with. The spin down was nearly pristine so I'm changing it out for a 100u screen, see what happens.Two units, one sediment and one charcoal. Just be careful. The entire rig comes with either a left water entry or a right entry, and I did not see this specified in the Amazon blurb. I redid my water piping but could have saved some trouble if I had picked the right one.Otherewise, I have used this same unit for more than 15 years. You will need the plastic wrench and extra washers, as well as some vaseline to go with the new washers when you change the filters. There is no indicator for when the filters need to be changed, however, although you can order clear cannisters at a higher cost (I did not).Listen, I live in South Texas out in the sandy area where iron and iron bacteria, hard water ate the plumbing out of a small house we leased. I installed these with a iSpring WSP-50 Spin down sediment filter, and a iSpring UVF55. Let me tell you, after flushing the system, and then tasting the water, I wept it was so fresh and amazing. I loaded these with a Pentek RFC-20 Carbon Filter 20", Pentek 155358, DGD-5005-20 Dual Gradient, and a Pentek 155263, RFFE20-BB Radial Flow Iron filter.I ran that output through the UV light and WOW .. the water is ... amazing. I am going to do another hard water test and see if putting a water softener will get me closer to pure soapy bliss in the shower, and I am going to add a reverse osmosis for under the sink to drive drinking water and ice maker , but for a whole house filter .. YOU cant beat this!!!I really dislike the o-rings...a lot. Plan on dropping the o-rings into the carton several times before being able to actually get it secured him before being able to actually get the cartridge threaded..The female pipe thread (FPT) are made too loose, and will leak. Use Teflon, and more Teflon, and perhaps more to be sure. I used a 1.25” to 1” TMA and had trouble, as the metal flanges are a bit tight for the larger fitting,Overall pretty easy to install. They are bigger than I anticipated. The outlet port on the last filter unit seeps a little even though I have wrapped it with a boat load of teflon tape (twice now). These are pricey but worth it to have cleaner water I guess.Easy to install but i probably wouldn’t buy this again for many reasons. For stater, the entire product is made from plastic except for the mount. The nipples that connect each big blue is plastic as well. Also the lack of air pressure release for each filter is annoying.If i have to do this over again, i would get one with a water pressure gauge for each filter and an air release for each filter as well. Pricing isn’t even great as you can buy one 20x4.5 big blue for about $60 with mount totaling 180, and you will need 2 male 1 inch nipple for $10 totaling $200 and will allow you to add a water pressure gauge as well to each filter to know when to replace.First order came and was damaged, returned it. replacement came and while reading the sticker description, it has warning that can cause cancer. whaaaatt! why do they even sell it? it should have been in the description to save us all of returning the product.Best deal for filter housings I could find. They didn't leak. We had to flip the mount 180 to accommodate our flow Direction.Was looking for a 4.5 X 20 filter and this system was very reasonable compare to some that were listed. Easy to install and i added a bypass for water to make filters changes quicker, works as advertise.So far so good. Easy to assemble. O-rings for the bodies come a bit warped. Just put them in warm warm for a bit before using.We purchased a set of these filter housings last year for another facility and everything was delivered as expected. Re-purchased and all three housings were shipped without the o-rings. I guess we will purchase them separately.