Blue Juice valve oil is a well-established and popular lubricant for brass instruments, particularly trumpets and other valved instruments. It’s designed for both piston and rotary valves and is known for its fast valve action and staying power. The product was developed by a trumpet player who was also a chemical / lubrication engineer, with the primary goal of creating an oil that minimized the need for frequent re-lubrication.

Purpose:
It’s designed for use on all brass instruments with piston or rotary valves, including trumpets, cornets, tenor horns, euphoniums, and tubas. 

Key Features:
Blue Juice is known for its:
* Fast valve action 
* Staying power, minimizing the need for frequent re-lubrication 
* Non-corrosive nature, suitable for all metal components of musical instruments 
* Anti-bacterial properties, which can help keep instruments clean internally

Popularity:
Blue Juice has been a popular choice for many years and is frequently recommended by musicians.