adult train conductor hat engineer hat. This authentic size-adjustable engineer's hat gets everyone into the spirit and fun of model trains. Measure head circumference with a cloth tape or a long two inch-wide strip of paper or newsprint. Wrap around head and mark the strip with a pen. Lay the strip flat and measure with a ruler or yardstick. Take a look at my other train buff stuff items. How long will it take? What aobut more than one item? EDtails make all the difference.