Xtreme White Plus is PIAA's best-selling technology. The very popular Xtreme White Plus Technology is now available in various style bulbs. Rated at 4000K and providing 110 watts of light from only 60 watts on high beam, these bulbs will provide a brilliant Xtreme cool white light that will light up road hazards and street signs long before a normal halogen bulb would. The Blue topcoat on these bulbs adds a slight blue tint to the lamp for enhanced curb appeal.
H4 = referred to as a 9003 / HB2
9004 = referred to as an HB1
9005 = referred to as an HB3
9006 = referred to as an HB4
9007 = referred to as an HB5