I don't need it very often, but on the odd occasion I do need it, then it is absolutely invaluable. 

It pays to be prepared and get get one of these  BEFORE you are stopped from getting into that shop/bar/courtroom/wedding or whatever.  Be prepared!

I just got mine out of the van. Its a typical example. Its short at two feet, because that is adequate to get up the majority of steps or curb stones, or up a step into a shop or onto a dance floor to chat up that fit bird!  It folds in half as most do, and weighs very little so I can easily carry and deploy it alone from my wheelchair. I can even pick it up again using my Grabber!

There are many manufacturers of these things and sellers all over the internet. Do yourself a favour and go buy one online! If you are a full time wheelie then you cant really justify NOT having one!

One hand is enough to lift or carry it much like a suitcase once folded up.

Longer ones are available of course, in multiples of feet. So 3 feet, 4, 5, 6 are all available. But what's the point of a longer ramp that you wont leave in your vehicle since its too big?  And longer than 3 feet tend to be a little flexible and weak for a full sized powerchair with an adult in it anyway. Or too heavy.

The step that this one is leaning on is my staircase. Now obviously I can get up that! It was meant to show how it works and how steep it is.

That step is tall at 10 inches. The ramp looks quite steep. But I use it on similar steps and curbs all the time in my powerchair without any bother. If its too steep then I just reverse up! Better than tipping out the back!

A 3 feet long one is both too big for leaving in the van and not long enough for two steps. A four feet long one folds twice. As does the 5 feet long version so is heavy.

These larger ones CAN do 2 steps. But while they fold up quite small but thicker and heavier they struggle with the weight of an adult in a heavy full size power wheelchair.  At least all the ones I have tried. If any other manufacturers wish to send some for me to check out then feel free!

So for automotive "keep with you" gear then longer ones are a step too far. The weight and inconvenience seems too much and they take too much space. Much better to stick with the small light 2 foot long one shown below.