These USA Kilts flashes are 5.5" tall. They have elastic which wraps around your calf and attaches with metal clips on either end and they're adjustable, so one size fits all. They have a slightly stiff backing and are great for beginners looking to save a few dollars.
Flashes are adjustable elastic garters that help to keep up your kilt hose. Pull up the hose all the way and wrap the garters around your leg, just above the widest part of your calf. Attach the metal clips on either end of the garter and fold the hose back down over top of the elastic. Roughly 2.5" to 3.5" of the flashes should be visible from under the turned over hose top.