GX pumpCS4 Portable PCP Air Compressor, 350W Powerful Motor,Max 5800Psi/40Mpa, Water and Fan Cooling, 5 Hours Continous Work, 12V Auto Stop Paintball Air Compressor

Works well so far. I filled my 90cc scuba tank. From empty. I do use an air moisture separation attachment. This really slows down the pump. It took 3 hours to fill from empty. My ninja bottle was topped off to 4500 psi in 15 minutes. It fills my air rifle tank in less than 5 minutes which is what it’s really designed for very quickly.

A very well made and funtional 5800PSI compressor. I have seen taredowns of these and they do not cut any corners in their engineering or manufacturing.

Good machine

Used this compressor a couple of times to fill my PCP and, wow. Great quality, worked right out of the box, no leaks, no problems. Haven’t used long term yet, but so far so good.Some stuff no one has mentioned/ details:1) The instructions are pretty good, and state that the air coming out of it is dry and suitable for breathing purposes. I wouldn’t, but that is what it says. It gives detailed instructions for first time and then repeat startup procedures, and is written in readable English. It also has a full exploded parts diagram and parts list.2) I went with a no-compromises set up, with an additional oil-water separator and an additional in-line drier and they *don’t seem to be necessary*. The compressor has a built in oil-water separator that works quite well! After filling, the bleed on my extra external oil-water separator was bone dry, and the bleed on the compressor itself spat out water as expected. I cautiously say you don’t really need an additional moisture solution if you live in dry or semi-dry climate.3) The air hose it comes with are standard air rifle Foster type quick-connects on both ends4) It wasn’t clear but the water cooling is actually a small very good functioning radiator and water pump. I was worried it might have just been a water jacket for the thermal mass, but that is not the case. The instructions say over and over to fill the water first before turning it on. Mine actually came with the water reservoir about half full of water already, so even if you were dumb and didn’t fill it, it probably wouldn’t have ruined the water pump outright.5) The AC-DC converter appears to be of good quality and works well so far.6) Comes with a quick-connect plug for the air line, and instructions that with the plug in place you should get 250 bar in 38 seconds or so. I confirmed this.7) Took about 10 minutes to fill my ~600 mL bottle from 100 to 250 bar, including the extra volume of the external oil-water separator and big drier. It would probably be a lot faster without the extra volume, as stated above in point #2. Since I have them, though, I will continue to use them.8) The automatic shut off with double-redundancy is, in my opinion, a critical safety feature. I couldn’t imagine filling a potentially dangerous high-pressure air device without one.9) Manual states it can be used vertically or horizontally, in case that matters to you.

Compressor arrived well packaged and protected. Only thing is that mines came with a crap ton of debris from the mfg and assy process in the water cooling tank. I had to run and flush it out multiple times until no visible debris is seen. USE distilled water to flush and when ready I add some performance inhibitor used in racing application. Fyi, the radiator coolant its purpose it to prevent rusting and freezing. The water is what carrys the heat away from the “engine” to keep it cool. I will update later on the long term review.

I'm absolutely thrilled with my new GX-E-CS4 pcp air compressor. As an avid air gunner, I was in the market for a reliable, high-performance pump that could handle my needs, and this one has exceeded my expectations.One of the standout features for me is the ability to pump up to 400 bar. I own a Huben GK1 air pistol that is rated for up to 350 bar, so having that extra headroom is fantastic. I can now fill my pistol to its max capacity without any issues. The compressor handles the task with ease, and I'm impressed by how quickly it can fill even my larger air cylinders.Another feature I really love is the water cooling system. I've had troubles in the past with other pumps overheating when filling larger volumes, but the GX-E-CS4 stays cool and composed even when I'm filling my 6 liter bottle. It's so convenient to be able to top up my air reserves without having to worry about the pump conking out.The price of this compressor is also amazing considering all the functionality and performance it offers. I was a bit hesitant at first, but after using it extensively, I can say with confidence that it's worth every penny.Finally, I have to mention the stellar customer service I received. I had a minor issue pop up, and the company was quick to diagnose the problem and send me a replacement part. Their responsiveness and willingness to stand behind their product is refreshing.Overall, I highly recommend the GX-E-CS4 to any PCP air gun enthusiast. It's a game-changer!