Maybe special forces, Black.
But looking at this exact model (looked up by the upc) buds is literally the only retailer selling this gun with that inthe description.
This is likely a typo.

Russell, the Canik's are Turkish Pistols originally designed for the Turkish Military. The SFx in the Model name is Special Forces x-tended for the longer barrel. Others like S Elite = Special Forces Elite, TP9 Combat Elite. Other designations refer to the variations of trigger/action, barrel, slide types. canikarms.com/en/series/tp-series/tp9-sfx

Russel, I think Paul is right. I have this gun and have never heard of S Forces BK 20R.