A "Keratin Hair Mask Brown 500ML" is a hair care product designed to nourish and revitalize hair, with the added benefit of a "brown" color.

Here's a breakdown of what this product is based on the search results:

Keratin Hair Mask: This is the primary product type. Keratin is a protein that is a key component of hair structure. Keratin hair masks are deep-conditioning treatments that are used to repair damaged hair, reduce frizz, and make hair smoother and more manageable. They are particularly popular for hair that is dry, brittle, or has been chemically treated

Brown: This is the unique and distinguishing feature of the product. The term "brown" indicates that the hair mask contains a pigment designed to enhance or deposit a brown color. This is not a permanent hair dye, but rather a temporary color treatment that can help:

Refresh brown hair: It can revive the vibrancy and richness of brown hair color, whether it's natural or dyed.

Tone or neutralize unwanted tones: Some color-depositing masks can help neutralize brassiness or reddish tones in brown hair.

Add subtle color: It can add a hint of brown color to a lighter shade, leaving it with a shine and a more uniform appearance.

500ML: This is the size of the product. 500 milliliters is a standard, large size for a hair mask, indicating it's meant for multiple uses, making it a good value for a regular hair care routine.