Coupler manages line pressure when you couple and decouple. When you couple, you don't push against line pressure. When you decouple a long airhose, you don't get the big bang: the coupler bleeds the hose pressure down to a low level before the plug is released. Impressive!

Provost couplers are built to stand up to 20 years of daily use in a professional setting and use more ball detents than the competition, giving a positive, even, and solid lock. Plus the button operation is a convenience versus the traditional ring you have to push down. And the outer coating protects whatever you are working on as well the coupler when it’s treated roughly and unceremoniously tossed on the ground along with the air line.

Hard to push tools on the fitting.

works perfect. press button to release is amazing! It will not let go of your hose until all of the pressure is out. no need to worry about the loud woosh and a flying hose.

**Update**Dec2021I have yet to replace a worn coupler! In fact, I have bought even more of them!Everything in my shop now uses the Prevost Highflo couplers. They do cost much more up front, but I have zero replacement cost since initial purchase and zero leaks!! Shhh listen… Hear that hissing leak? No? Me either!I added a wear/tear picture of the original coupler. Shiny spots are just shiny, no grove to catch a fingernail. You can rebuild these if and when they do leak!**Original Review**This is the best air coupler system I have ever used! No more hose coupler blowing air in my face/ ears. Easy to use! Just point the receiver end in a safe direction, away from you or other people, Push and release the green button and the coupler ejects the plug and releases upstream air (from coupler connection to the tool). Best part is that it holds the plug in the housing until all the pressure is released. Then you pull the plug end out of the coupler. NOTE: pushing the green button holds the plug end in the coupler (think Safety, it doesn’t shoot out) and you can’t separate the plug from the coupler while the green button is pushed! Momentarily push green button, air released, then pull hose to separate plug from coupler.The common complaints for this coupler is that it leaks on arrival. I believe this to be because of an assumption that it works with any type plug, This is NOT a universal coupler. In this instance, Prevost PRVESI071201S will ONLY work with Prevost 1/4” FNPT or MNPT, High Flow Safety Air Plugs. Don’t bother using China Freight, local hardware or discount home store coupler parts. Best advise I can give the DIY/ home shop/ hobbyists is buy two or more of these couplers and a bag or two of 10 plugs the first time. I have used universal HF and Orange Home store couplers and I have replaced leaking couplers over and over. When I think I am upgrading, it’s just been kicking a crap coupler and plug set down the road just long enough to forget when I replaced them. I’m done, this is a steel ball coupler that only uses matched steel plugs. No more worn aluminum plugs in crap ‘world supplier’ parts.

I’ve always been looking for the perfect air disconnect for my garage and I never found it until now.Some of the others that I have tried are very difficult to disengage. Hard to grab and never really sit properly without leaking. This one is fantastic.Press the button and it quickly disconnects with no leaks or anything.Even plugin the tool is painlessIf you are like me and are looking for the ultimate in air tool disconnects. This is for you.Yes they are more expensive but You will not be disappointed.

I've been using this Coupler (and similar Prevost HIgh Flow Couplings) for about a year now, and I think it's fantastic.NOTE! THIS AND ALL "HIGH FLOW" PREVOST E07 SERIES COUPLERS ARE NOT INERCHANGABLE WITH "1/4-inch-body-Industrial aka Milton M Style" OR "3/8-inch-body-industrial aka Milton G Style"This is very important, because if that's what you expect, you'll be disappointed.What this is, is a "1/4-inch-body-High-Flow-Interchange aka Prevost E07 Series aka Milton V Style" coupler. Note, also that 'coupler body size' and thread/connection/hose size are completely independent. I believe Milton has a pretty good resource for clarifying thisWhy is it awesome?-Prevost E07 Series* (or Milton V Style) Couplers and Plugs have more than 2x flow area than the 'typical' 1/4" Automotive or 1/4" Industrial fittings. More flow area is less restrictive, allowing for more flow, and improved air tool performance. You might not notice if you're just using an HVLP spray gun, or filling tires, but my Pneumatic impact gun is at a whole new level with the 2x restrictions of 2 box store 1/4"-body couplers in the way. One photo shows an end-view of the High Flow Interchange plug vs the Industrial Interchange Plug.-The coupler body is barely (if any) bigger than any other 1/4" Body coupler. A Prevost Safety ESI coupler is shown in my photos besides a Prevost Safety ISI coupler in my photos. This is especially awesome because in order to get another coupling standard with similar flow properties, you have to step up to a 3/8" Body standard (such as the Milton H Style/Prevost I08 Series 'industrial 3/8' or Milton P Style/Prevost U08 Series 'Automotive 3/8' standards). Stepping up to a larger body series makes the tools heavier, bulkier and more difficult to manipulate/move and use. This matters a lot to me, because I'm not fully able-bodied, so the weight and size savings are excellent.-I put the fact that it's not compatible with 1/4" body fittings as an advantage, that way I can keep my oil-mist hose with the High Flow couplers separate from my Industrial coupler equipped cleaner-air hose for the tools that need air at least through a coalescing filter.-the 1/4" NPT fitting threaded right into my hose end, so I didn't need adaptors/connectors/nipples to make it work!-This is a 'Safety' coupler- which means that it releases downstream pressure before allowing physical removal of the male plug connection. Since I put it immediately after my regulator, I can safely disconnect my hose without worrying about losing an eye to 'Hose Whip.' When the coupler is pressurized, simply pressing the button once releases the pressure in the attached hose, and then once the pressure is gone, allows the hose to be removed. If you don't want to wait, or won't ever put a hose in the coupler, look for an ERC model instead (E for High Flow, R for regular, and C for coupler)-This is made by Prevost. Using it, it feels like the gold standard in how couplers should feel in the hand, connect, wear, flow, disconnect and most importantly, SEAL. Legacy (which encompasses a lot of brands, like Flexzilla and Milton I believe) makes decent stuff, but the build quality and design effort in all of Prevost's stuff is superb. For instance, instead of a simple plate at the bottom of the connector, there's a machined piece with fluid pathways to manage turbulence & its effects on flow through the coupler.All in all, this system (Prevost High-flow E07 Series aka Milton V Style) is great, but the quality, flow properties & ease of use of this specific unit is outstanding.(Forgive me if I'm using odd terminology, I haven't found a better way to call this thing, The model number, ESI 071253, indicates E for High Flow, S for Safety, I for 'new' style composite bodied coupler, 07 for the diameter of the coupler at the o-ring, and then the 1253 are for this specific male 1/2" NPT connector)