Back in the time I spent as a delivery guy (over 15 years) I was a bundle of surprises. One of my favourites is a piece of steel pipe, around 12" long and about an inch and a quarter I.D. that lived on the door side of the driver's seat. The official reason (and most common use) for it was because I'm a skinny guy. It fit perfectly on the end of my tire iron, to give me the extra leverage needed. It also happened to fit very nicely in my hand, with my fingers closed around it and slid very tidily up my sleeve to rest between wrist and elbow (underside of left forearm). A twitch of the wrist and it was in my hand, otherwise it was an excellent blocking tool to any thing heading my way.
Steel-toed running shoes (so I could deliver to job sites - yes that wasn't uncommon) meant that any kick counted for extra, and even these days I can till snap a front kick that'll catch a jaw and put a head on upside-down and backwards. It just costs me more now than it used to.