Ha ha... The ones we used for Patriot stuff wouldn't do you any good - they were made to fit around a round computer monitor.
I'd say just print up what you want, cut it to fit the back of your beacon, laminate it (can be done with clear packing tape yourself or at Alphagraphics or Kinkos or something) and then tape it on to the back of your beacon (assuming your model doesn't have buttons on the back or something). That way it's not getting lost, wet... and you'd see it as soon as you pulled the beacon out.