I am probably sounding like an ad for them but I get mine from www.powercallsirens.com they have many already made up and if not they will work with you to make up what you want....you can get them in regular material or in reflective....check them out.....Stay safe....Keep the Faith....Paul
Don't bother buying them here (except for a collection) because they certainly won't stay on your helmet! Unless of course you're talking about my 'HA', 1st Aid and name sticker? Oh, and the Croation Football Association one, can'[t forget that...
I've gotten mine from firefighter.com thefirestore has some cool stuff too.
I wish dept's would regulate what ff's can put on their helmets. I took mandatory at a dept. that seemed to allow just about anything on their helmets including decals like "princess bi*ch" (with a pix of tinkerbell by it,) "rehab is for pus#ies," and my personal favorite "f*ck off." Yup, this ff actually had "f*ck off" decaled on his helmet. Just gives a bad name to the fireservice when in public eye. Please be respectful when customizing your helmet.
I am putting two reflecting black and silver flame ones on the front, a pair of black reflective (these are sweet) and a red line and flag tetra on the back of my new leather. Check out thefirestore.com and firebarn.com.
Here's the ones I ordered from Weston Signs. They're on our Vertical Rescue helmets...
And yes, I know the karabiner is upside down, but when it's connected to the rear dorsal D ring of your harness, it can be a bit hard to reach around and turn, especially once loaded.