From him: As the name suggests, being an "Advanced Master Gauge" pump, this is a tool that's intended for users that have already done some self exploring with cock pumps and are ready for something more on their level. This means, however, that there's nothing in the way of directions that come with this tool, the only mention of use just states the standard warnings: Don't make it hurt, could cause bruising, ect.

So, instead of just putting it on and pumping, I looked it up online. It gave me a few more specifics, but using a cock pump is pretty simple:
Use lots of lube to get yourself in.
Make sure there's a good seal on the base.
When secure, pump until there isn't any more air left in the chamber, and you can feel the suction.
Leave on for a couple minutes to achieve total effect.
Press the pressure release button on the top of the chamber and withdraw.
Enjoy your slightly larger cock for a little bit (up to an hour)

From him: This is made with a couple different materials. First, there is a soft silicone ring, or "donut" at the base of pump that cradles your cock and provides the seal around it. This is fully and easily removable for cleaning, and holds up very well. Because it's silicone, you're going to be able to fully disinfect it, so use a 10% bleach solution or throw it in your dishwasher. It's stretchy to easily accommodate most sizes of cock, but the opening is 1.2 inches, or 31mm at the relaxed state, so if you're small, go for a different pump. The maximum size of the tube at the base is 2.5 inches, though, if you're that large already, you probably don't need a pump.

The tube itself is made out of hard plastic, and has supportive ribs running up and down the length of it. Additionally, there are measurements molded into the plastic itself, to show length of the cock within. The molded part is important, as it won't rub off with repeated use, and is a pretty nice touch.

From him: The pump itself is pistol style, you just pull one lever back towards the handle, and repeat. Very nice, solid construction, and powerful. Simple to use.

The sheath of the actual chamber is very nicely designed, the ribs add look and support to the vacuum chamber within, and flows at the top into a black plastic cap, which integrates smoothly into the overall design. There's a pressure sensor at the top with the cap, and it is molded into the overall construction. Everything is purpose driven, and thought out.

The hose connecting pump and chamber is removable, so you can clean it, and if need be, somewhere down the line replace it if needed, or if you just want a longer hose.

This is also a large toy. 2.5 inches thick, and about 20 inches long, and that's just the main chamber housing. It's not very subtle, so hiding it away might pose a problem. I wouldn't travel with it unless you have a secure area in your luggage.

From him: This toy has a couple moving parts, so a little attention is required to keep things working perfectly. You don't want to get the pistol gripped pump gummed up, so clean hands should be considered when you're working with it.

It pulls apart into four sections rather easily, the tube connecting pump and chamber, and then the pump, chamber, and silicone 'donut'. All are easily washed with soapy water, and the 'donut' is able to be sterilized, either with a 10% bleach solution, or throwing it in your dishwasher.

Lube is required for use of this toy, and as always, we recommend using a nice easy water based lube. Makes clean up easy, and works very well for all materials involved.

From him: This was packaged in a pretty simple paperboard box, with pictures and descriptions covering the faces. It's somewhat flimsy, but due to the size, it's also handy for storing the pump. Just need somewhere to put it, as it won't fit in any of our toy chests, we actually are keeping it in the closet for now until we can get something bigger.