(Haven't had this a long time, but I will update this as time goes on to add any longevity pros or cons as needed.)I find that typically air mattress manufacturers consistently over-state their mattresses' size. "Queen" is typically equal to a regular bed's Full/Double, and "King", if offered, is typically a regular bed's Queen, etc... Sizes are always a weak point with buying & using an air mattress, even good ones, so I will try to be as thorough with sizing as possible and not dwell on the stuff you already know and that most other reviewers have mentioned, like height, built-in pump, ease of use, etc, stuff that applies to any size King Koil and that you probably already know. (See my pics for actual shots of laying in it for perspective).I ordered King Koil's "California King" and I have to admit, it's actually close- it's more a blend of the dimensions of a regular King (76x80) and a California King *(72x84). *Yes, California Kings are 4" narrower than regular Kings, but 4" longer.KING KOIL CALIFORNIA KING MEASUREMENTS:OVERALL:73"x86" by my best attempts to measure (round edges make it hard to get an exact when using a tape measure)... counting outside the top edges only, not any extra side bulges. So, this is NOT counting how much room you'd need in a tent necessarily. This is fully inflated with no weight on it. Expect some minor increased width requirements when actually sleeping on it.USABLE SPACE:63x80" counting the pillow end.MORE DETAIL:~63" wide, x ~80" length counting the pillow edge to inside the foot edging, or about 70" length inside the pillow & foot edges. (In the pic of my legs, I am laying my head inside the pillow end, and I still have plenty of room with no danger of my feet poking out the end. I am 5'8" tall.MY IMPRESSIONS:Even only counting the usable space, the size of this one is still acceptable to me, since this places it with still 3" more usable sleeping width than a regular bed's true Queen mattress. Score!The "Queen" sized air mattresses offered by KK and most other manufacturers, being smaller than a real Queen bed, don't allow for very comfortable 2-person sleeping, unless you can deal with the always-touching, 'snuggling' kind of partnered sleeping. While there's a time for that, for my wife & I it's not all night while catching some Zs camping.INITIAL SETUP:OK I said I wouldn't dwell on this, but I'll touch on it- The pump inflated this King sizer in somewhere between 4-5 minutes, and it sounds like a quieter-than-most vacuum cleaner running. It has power-deflate, which is a nice perk that many built-in pump mattresses do not have.When fully inflated the first time, I gently got on. Not sure if you're not supposed to or what (the manual has NOTHING about initial care & break in), but I did to listen for leaks. No leaks, yay! Spent about 2 minutes on it, then got off to let it stretch.I let it sit undisturbed for 4 hrs. Then I laid back down on it. It felt full- great support! After I got off it I realized it had lost some air, the sides were quite squishy. I topped her off for several seconds until full again. The great thing about knowing this is that even when it loses some air it still feels great, supportive. No sag. Obviously there's a point where it will sag if it's low enough, but even when needing a minor top-off it feels great!COMFORT:I find it comfy for what it is. Not "hard" but not overly squishy. All air mattresses will have some bounce when a partner moves beside you, so of course you should expect that going in. But this one does a good job at minimizing that compared to previous air beds form other makers I've used. The flocked top does nothing for comfort really, since it's not squishy, but it helps not be noisy when you roll around on it, creating that awful balloon-rubbing sound. And if you add a squishy memory foam topper under the sheet you'll be in great shape!CLOSING THOUGHTS:King Koil's "California King" air mattress is recommended for being a few inches wider than a regular Queen bed (and MUCH wider than ALL so-called "Queen" air mattresses!) and right about the size of a true California King all said & done. It's big, and great for 2 people who need their space. If you're using this for camping, make sure your tent has these dimensions and then some, or at least test it out in your tent at home before you head out!MY PICTURES:1) The mattress with 2 standard pillows for perspective2) My feet when laying with my head inside the pillow end. I'm 5'8" and there's plenty of legroom, even more if you use the pillow end. (Side note- these socks are great, I need to review those too!)3) Me laying comfortably inside one edge. As you see I take up 3 runs of indentations (I'm 5'8, 200lbs). Another person my size would leave approx 12" space in between both people. Finally!