The BOB Keen Black Waterproof Pencil Gel Liner Kajal is a popular, budget-friendly eye makeup product designed to provide the intense pigmentation of a gel liner with the convenience of a pencil. It is known for its creamy texture, deep black, matte finish, and long-lasting, smudge-proof, and waterproof formula. 

Brief Description:

• Formula: Gel-based pencil that glides on smoothly without tugging or pulling, offering a creamy, velvety texture.
• Color & Finish: Rich, deep jet-black color with a matte finish.
• Performance: 24-hour long-lasting, waterproof, sweat-proof, and smudge-proof formula, suitable for oily skin.
• Versatility: Can be used as both an eyeliner (on the lid) and a kajal (on the waterline).
• Type: Traditional sharpenable pencil (or sometimes found in retractable, depending on specific batch). 
• Origin: Manufactured in China. 

How to use:

1. Preparation: Ensure the eye area is clean and free from excess oil or moisture for the best, longest-lasting, smudge-proof results.
2. Application: Gently glide the pencil along your upper lash line, lower lash line, or the waterline.
3. Intensity: Apply in one smooth, quick stroke for intense color.
4. Blending/Smudging: For a soft, smoky look, blend immediately with a brush or finger before the product sets.
5. Sharpening: Sharpen the tip as needed to maintain precise, clean lines. 

Customer Benefits:

• Intense & Bold Definition: Delivers a high-pigment "so black" finish that enhances the eyes.
• Long-Lasting & Smudge-Proof: Stays put all day, resisting smudging, fading, or transferring, even in humid conditions.
• Waterproof: Withstands sweat, tears, and water.
• Smooth Application: The creamy, soft texture ensures a comfortable application on the delicate eye area.
• Versatile Styling: Perfect for both dramatic winged cat-eyes and soft, smoky eye looks.
• Gentle on Eyes: Often formulated to be non-irritating, making it suitable for sensitive eyes and contact lens wearers.
• Budget-Friendly: Offers premium, long-lasting performance at an affordable price point.