£15
Lifetime Guarantee (Except for the flint wheel).
The flashers use a flint wheel, which can be obtained worldwide; these are taken from a Clipper lighter.
Perfect for creating a small flash from your hand. Unlike electronics, it won’t let you down at the last minute.
NB: The current ones I have in stock vary slightly from the picture; they have a different finger hold (more sturdy, I think!).