I see no significant difference between these and brand alternatives. The "steps" at which the spray is adjusted aren't as strong and the inlet diameter is a tad smaller, but that, apart from the price, is about it.

I'd return these if I could though. They don't mix with normal drippers on the same zone, none of these bubblers do, they only work if you have nothing but bubblers in the entire zone.

The water output is just extremely high. If you open it far enough to actually get streams projecting some 6" outward, each of the 6 streams yields more than 2gph, so you put out some 15gph/sqft with this. Mixing drippers (.5 to 2 gph) with sprayers (10-20gph per 10-20 sqft) works, but these bubblers here completely drench their area in 5 minutes, while drippers need a half hour to provide enough water.

Have bought a couple drip watering kits and none of them has all the parts I need. Now I figured out the cheapest way to build a good drip watering system for a small garden after trial and error and you can save some money from my experience.
one pack of this 50x emitter
1 to 3 pk DIG Drip Irrigation Watering Kit (G77AS) $12.54 (HomeDepot in store)
several pks Orbit DripMaster 67431 1/4-Inch Barb Assortment, 30-Pack $1.67 (Amazon Add-On item) or other similar product
use the 1/2" tube and hose connectors from DIG kit to build the main line
use the 1/4" tube from DIG kit and connectors from Orbit kit to branch out to build the emitter lines
The emittors work fine for me thought the far more expensive name brand emittors look a little bit better.

I purchased a 50-pack of these drip emitters and am very impressed. I used this in conjunction with 1/4" tubing from Rain Bird (https://www.amazon.com/gp/product/B0049PJMYC) and an Orbit 67000 Apollo 8 manifold (https://www.amazon.com/gp/product/B000H9AI9C). I can control watering from my cell phone anywhere in the world with the RainMachine Mini-8 irrigation controller (https://www.amazon.com/gp/product/B00WQI65V2).

Now, to the product specifics. I don't think the emitters use super high-quality plastic that will weather multiple seasons well. However, you get 50 in a pack and can replace them cheaply and easily. As we have extremely hard water in my area, I expect to replace these regularly. It just isn't worth buying expensive emitters.

Despite the warning in the product listing, it wasn't difficult to attach my 1/4" tubing. I didn't need to use hot water or a phillips screwdriver to stretch the tubing.

It is easy to adjust the flow from almost nothing to a fairly large flow. Just be sure to monitor your waterings on occasion to make sure there aren't any malfunctions. I have attached a video that shows these emitters in action.

We have a lot of calcium in our water, so I have to replace my emitters pretty much every spring. These are great value for the money and should keep me going for the next couple of growing seasons.

Don't mess with the whole hot water business to make them fit into the water lines. I just poke a phillips-head screwdriver into the hole, twist it around until it goes in about a half inch, then quickly, before the line regains its shape, shove the emitter in. Makes it very easy, and you do want them to fit tight, so as soon as the lines regain their shape, the emitters fit as if they were molded as part of the system.

They are hard to insert into the 1/4" tubing, impossible bare handed for a female, but heating the tube up in the sun helps immensely. I would say about 75% of them work, which is a bit frustrating when they are so hard to insert. But these annoyances are minor when compared with the cost savings of this pack.