"TruVision Dome Bubble Spare, Smoked, for HD-TVI flush mount domes. 6"" bubble replacement done. For use with Truvision HD-TVI PTZ flush mount domes. The TruVision Replacement 6"" smoked bubble dome can be used to replace the standard clear bubble in TruVision HD-TVI flush mount PTZ cameras. The smoked bubble provides a way to partially obscure the position of the PTZ camera."