I have been carrying a Victorinox Swisslite on my keys for about 6 months now. It it utterly indispensable.
It is a 54mm tool that is basically a classic, with one scale tool swapped out for a small LED bulb.
The tools are a small blade, which is very fine at the tip, and comes very sharp. It is a great high polish, highly resistant to corrosion steel. The same steel on any other SAK knife. I use the knife for all kinds of minor tasks, but most often it seems I use it for opening bubble packaging. It does this well.
The scissors quality and uses are well documented. The spring did fail on mine in the first week, but a new one was a five dollar fix. The blades are sharp and cut thing you wouldnt expect, like aforementioned thick bubble electeonics plastics.
The file and flathead combi tool is a great keychain tool. The driver will clean under nails in a pinch. Together with the scissors, (which will cut even my thick, gross toenails if you cut close to the pivot) you have a full nail care station.
The flathead will fit most phillips screws due to its steep shoulders.
The spare scale spot comes loaded with toothpick, but the package includes the tweezers too. I chose to keep the toothpick as I carry separate keychain tweezers.
The LED bulb is operated by pushing the shield.
It takes a small lithium battery that slides into a little secret door on the side of the tool. You can push the battery out when its time to change it with a pen, pin or tweezer.
The LED is of minimal brightness, clearly geared towards longer battery life. This is conpletely reasonable IMO, as even a small amount if light is utterly appreciated when all others are out. Changing the battery is a bit fiddly too, so the less I have to do that, the better.
Overall, what you get with this tool is an ultra minimalistic, but complete, full EDC setup if knife, torch and scissors. For some people, this little MT will be all they need to carry. The weight is so negligible, and unlike other keychain MTs which have easily chippable Alox scales, the plastic wears better. Scratches and scuffs on plastic are far less obvious than silver poking through colored Alox.
The other options for this exact size is the rambler with its multi function driver and opener, or the signature, which has a pen in place of the light. Each are great on their own merits, but I think having the small bulb is of higher utility.