I live urban and my keychain contains a portion of my emergency EDC . So there’s a Medium size Bison Tube whistle, a Medium size Bison pill fob ( chewable aspirin, generic Benadryl, ibuprofen, generic pseudofedrine and caffeine tablets), the pill tube is wrapped in 12” of 2” Gorilla tape, A modern repro of the Paul( slide-out) Knife [ ingenious ininvention that it is], a yellow Mini-Bic lighter ( electrical tape under the trigger to prevent accidental loss of gas) , lighter inverted in a rubber tire sleeve sealed and grommeted on top ( for waterproofness & to cut into tinder). ), P-38, Utilikey, generic key type screwdriver/ 1/4” driver/ pry tool combination and an old model Fenix E-05, backed up by a Yellow light Photo Freedom ,carried reversed in its neck fob,( two is one..etc.). EO-5 is twist type, less accidental turn on risk , same reason for reversing the Photon in its carrier. Casts enough light to be useful and is relatively long lived with a lithium battery. I added an after market pocket clip, mounted backwards to hang from a hat brim, if necessary. the E-05 is barely bigger than it’s battery , lightweight , bright enough, long burn time , especially on low, and almost bombproof. I’ve considered replacing the E-05 with a Lummintop AA, a better light all around. But the Lumintop is too big,long and heavy for my already over burdened keychain, which also , of all things, carry’s my keys.