Silver Bullet Fastlane Envy 25mm Straighteners - BlackEnviably sleek, smooth and frizz free hair? It's got to be the Silver Bullet Fastlane Envy Hair Straightener. Created by the hair geniuses at Silver Bullet, the secret to this streamlined, salon quality hair straightener is its ability to maintain constant temperature, even at high heat. Constant temperature ensures a superior result, sealing your hair cuticle to perfection, while reducing friction and preventing damage.