Master Plunger MP100-3 Heavy Duty Toilet Plunger Clears, Kitchen Sinks, Garbage Disposal and, Toilets Fast. Equipped with Patented Automatic Air Relief Valve, Black

This plunger is the best I've used, and the non-overflow valve is great feature, but no instructions about it are included. It is even printed on the unit itself, "Automatic Overflow Valve" and "Insert Slowly to Prevent Overflow (on top - see pix). It's not totally automatic though. I took some pics to show how it works, there's a slot cut in the threads of the handle that will bleed air out of the chamber if the handle is not tightened securely. With the handle tightened, there is no air bleed however and you would risk an overflow. They should make that clear.I have one of those new "smart" toilets or whatever they're called, the combo bidet (I got a Moen brand). The outlet at the bottom of the toilet is sort of square and I wondered if this would be soft enough to seal completely at the bottom. It's not super soft and flexible by it's nature so I wasn't sure if it would make a good seal at the base, but it didn't matter, because it moves such a large volume of water. This plunger displaces such a large volume of water that on both the plunging downstroke and the suction on return stroke, that it does an amazing job.With the blockage, smart toilet would flush slowly but it detected a blockage so it shut down and refused to flush until it was cleared. I plunged (up and down - water going both directions in the drain pipe) once, and it improved the flushing, but not to 100%. One more time did the trick and it's totally back to normal. EASY! EFFECTIVE! I love this plunger. Cool color too.I saw in comments that some had issues with it not performing that well and I think maybe the handle was in the "vent" position (not screwed on tightly), so some air bleed may have affected the plunging performance. When I got it I wondered how the "Automatic" valve works and it was obviously the slot in the threads providing the air bleed, and it would be sealed by tightening the handle. I tested that on the floor with a rug as a seal, and that's indeed how it works. It's a great feature, just too bad they don't print some simple instructions. Possibly some people used it in the "vent open" mode. I figure that you could probably just leave the handle 1/2 turn loose and insert slowly into toilet to avoid overflowing due to displacement of the water by air in the plunger as it escapes out the threads, and then just plunge away. It has so much volume when plunging, it would probably work fine even with the "valve" open with vigorous plunging. But if you tighten the handle after inserting the plunger in the water, it seals completely and really plunges away! It moves an amazing amount of water in and out, and cleared things up almost instantly. I wrote up some instructions that might prove helpful if you get one of these. I would definitely recommend this plunger.

Best plunger in the world. I have used for a year and it works great.

EDIT: I am updating my review on this plunger. I was given a replacement due to the faulty one I originally received. I immediately saw a big difference in the performance of this replacement since there were no hole/cuts on the folds. It definitely holds a strong air seal and was able to unclog my toilet after a few tries. The handle still bent on the new one but I was able to bend it back without any damage. Air still escapes a bit through the area where you can screw the handle closed, but it isn't as bad as the last one and I don't think it affects the performance too much if at all. I am giving this 4 stars only because the quality of the plastic isn't the greatest, especially when the handle bends to easily. If the handle wasn't hollow, the plastic was more durable and had a rubber ring at the bottom .. this would be a 5 star product for sure. But this is a pretty decent plunger and it definitely holds a strong suction. This works PERFECTLY for clogged sinks and tubs though.I had previous plungers with this exact same design and they worked perfectly .... and of course when I needed to replace my old plunger, I went straight for this one .... but I am so disappointed in this purchase. The whole plunger is entirely made of that cheap hollow plastic that those children's plastic kitchen sets and playhouses are made of, which easily dents. The one I had before was made with thick durable plastic and rubber ... there is NO rubber on this plunger. The first time I tried it ... I noticed a ton of bubble seeping through the folds and when I checked it . there were slits and holes in a few places ... so there is no way this plunger can hold an air seal as a result. The bottom handle area where you can loosen and tighten the handle closed is not sealed well at all; even when I tighten the handle as far as it will go, there is still tons of air the escapes, resulting in no air seals. The handle (which is completely hollow) also bent sideways the very first time I tried to plunge the toilet. I possibly could have been sent a defective unit .... but the other design flaws make me think otherwise.

It seemed a little high priced when I bought it, and seems a little thin, but it sure clears the pot fast. I'd had colon surgery some years ago and part of the result of that is that I have really big poops that often clog the pot. The accordion design of this sends a load of air pressure that sends it all right down, so far one shot does it every time. I hope it lasts, it's doing a great job.

I only bought this because the color matched my bathroom decor. It was a waste of money.There are far better, more efficient alternatives that all cost less. This thing may be good for deep water. Too bulky for regular toilet clogs.It’s big and the pleated part at the bottom can and does get toilet waste all in between it- yuk.The few times I had to use this, I was disappointed. Just buy a regular plunger, this is a waste.

Su funcionalidad es única me agrada porque efectivamente destapa el caño

I bought one of these from Home Depot in Canada 🇨🇦 roughly 10years ago & still have it till this day as I’m extremely happy with this design as with such little effort that you can unplug any toilets/sinks within seconds; Forget about calling any plumbers as you can do this task with such little work & in no time @ all; Why call anyone when you can do it all your own two hands.So I ordered 2 more so I can have one in my 2nd/guest bathroom & another one inside my laundry room just in case I need it for anyone of my bath/showers as I needed one in the past & didn’t want to use the plunger inside my bathroom for it.& it was delivered two days ahead of schedule even with CanadaPost being on strike.So I give you Amazon.ca Two Thumbs up 👍🏼 👍🏼

I purchased this because it’s exactly the same as the plumbers use

Funciona pero es un poco caro, ojalá sea durable porque como se usan poco, el día que los necesitas, ya no sirven por cuarteaduras en los plásticos.

Excellent! Worked a like a charm on the first try. We are very happy with this plunger. We didn't experience any unpleasant overflow and mess when using this plunger. You are supposed to turn the handle a quarter of a turn to prevent water and contents overflowing over the top of the toilet bowl. It didn't come with a card of instructions. The instructions are on the actual rim of the bellows. They are a bit hard to see, but you can see them if you look closely. This is a plunger you want to keep handy.