This is my main EDC as it also doubles for CCW of my off-duty if I don't feel like carrying it on my person or clothing doesn't permit.
It has enough room/zippered pockets to carry some things I find useful/essential. For example;
SIPIK-clone AA 7W 300 lumen flashlight. Has high, low and strobe functions and flood-to-focus.
Small AAA mini-maglight
I also carry several fire sources such as a magbar and small ferro rod with cottonball/vasaline tinder.
Small folding pocket knife i
Waterproof bag with a small first aid kit, extra batteries, floss, whistle, 10z bottle of 2% tincure iodine, compact mirror (Dave recommends this), chapstick
Two gallon-sized freezer bags
Couple of rain ponchos
Couple of space blankets
On a ring with my Swiss Army Tinker I also carry another AAA mini-maglight, small ferro rod and one of those old Marboro multi-tools which makes a great scrapper for the ferro rod.
I also carry a Spyderco Endura (serrated). Both this and the Swiss knife I've carried for nearly 20 years. Great knives.