Bayonet Gamma Doppler Factory New is a Covert knife skin in CS:GO that was added to the game in June 2016 as a part of the Gamma Exposure Update. The Gamma Doppler skin can be obtained by opening one of two CS:GO weapon cases, them being Gamma Case and Gamma 2 Case. The knife is available in only two exteriors, Factory New and Minimal Wear, and can have the StatTrak attached to it.
The Bayonet Gamma Doppler knife was painted with black and silver metallic paints, then candy-coated using a marbleizing medium which gives the blade its signature look.
Since Bayonet Gamma Doppler is one of the most sought-after knife skins, its price definitely reflects that with the cheapest Factory New exteriors going for around $500 and depending on the quality of the exterior, reaching well over $1300.