The basics Bumble and bumble Straight Conditioner is a light conditioning rinse designed to tame curly, thick, unmanageable, unruly hair.  The benefits Straight Conditioner is free of formaldehyde, cysteine, and lye and is safe for color-treated hair. The uses Formulated with Concen-straight Technology™.  The bottom line To tame curls and reduce frizz for a smooth, silkier texture.