The classic Sawed-Off deals very heavy close-range damage, but with its low accuracy, high spread and slow rate of fire, you'd better kill what you hit.
It has been spray-painted using a snakeskin stencil in patches that have been outlined freehand.

This skin is available in wear conditions from 0% (Factory New) to 100% (Battle-Scarred).
The values were set by the game development.