Chris Brown wears Ray-Ban RB3447JM sunglasses with Camouflage Grey/White fabric in the music video Fun (Pitbull).

These glasses are the standard RB3447 round metal sunglasses with gold (arista) frame, but come with hand mounted camouflage fabric. The RB3447JM model is also available in other camouflage colors or look for the RB3447 (without "JM") for other colors.

Find these glasses on Amazon or on GlassesUSA.

Reference: Ray-Ban RB3447JM 171 Gold Frame with Grey/White Camouflage round sunglasses