Got hold of a few of these, and they are dead handy, and very very bright, specs are:

Size: 40mm (L) x 22mm (W) x 8mm (D)
With 1 LED WHITE LIGHT
2 Light ON Mode: ON/OFF Switch & Pressure Depress Switch
Each installed with 2 x CR2016 Button Cell battery
Visibility: Over 1 mile



Colour is hit and miss with what I have left, but if anyone wants one for £1 just gimmie a shout at a meet or the rock.