Always the correct part
Beach RC says...
Traction Juice Bottle with Brush Tip
The 4oz Traction Juice Bottle ergonomics is just the right size for small or large hands made from a translucent bottle for easy checking of how much sauce you have remaining, cleanliness of the solution and type of solution.
The replaceable brush tip is specifically designed for off-road use. With the brush tip, you no longer have to use both a sauce bottle to apply then use a separate brush to apply. This is ideal for those who are tired of having their hands dirty from different tire sauces and chemicals.