Butterfly Knife | Doppler Black Pearl (BFK BP) was added to the game on March 15, 2017, alongside the "Take a trip to the Canals" update. The skin is available in cases "Spectrum" and "Spectrum 2".
The blade of the knife is painted with metallic paints and adorned with a pattern of translucent wavy lines resembling smoke. The color scheme of the skin includes various shades of blue, purple and crimson creating gradient transitions. The handle is unpainted and complemented with dark blue inserts.
Float Value of the skin ranges from 0.00 to 0.08, which makes Butterfly Knife | Doppler Black Pearl available only in Factory New and Minimal Wear condition. At levels of wear close to the maximum, the knife has noticeable scratches and abrasions located along the cutting edge.
The pattern index affects the ratio of colors as well as the location of blue, purple and crimson areas. Special or rare variations of the pattern are absent.
The quality of Butterfly Knife | Doppler Black Pearl is Covert. The skin has a StatTrak option and is the rarest, but not the most expensive phase of the “Butterfly Knife | Doppler” series.
“Doppler Phase 2” is one of the most popular skins for M9 Bayonet. The skin has a very large number of fans and is considered to be more valuable than phases 1, 3 or 4.