I don't carry a spare H4 bulb all the time, but when I do it's in a short section of black insulation for 1/2" plumbing. I put a bit of paper towel around the glass part first then put it in the insulation tube then put that all in a ziplock. I tried cases and medicine bottles, but any bottle large enough to take the H4 flange was pretty big. Comment on the original list. I take more gloves. Gloves for dry and gloves for wet and gloves for cold and gloves for . . . . Fewer underwear and socks (you replied to this idea earlier).