Serious riders know that using the right oil is key to keeping your bike running strong. This is Bel-Ray's top-tier EXS Full Synthetic Ester 4T engine oil. The 'Ester' part means it's a super high-quality synthetic base oil that offers excellent protection under extreme heat and stress, reduces friction, and helps keep your engine clean. The viscosity is 10W-50, which is a great all-around weight for many sport bikes, adventure bikes, and high-performance motorcycles, providing good cold-start protection and stability when the engine is hot. This comes in a big 4-liter (about 1 gallon) bottle, which is enough for an oil change on most bikes, maybe with some left over for topping up. Always check your motorcycle's owner's manual to make sure 10W-50 is the recommended grade. If you want the best protection for your engine, especially if you ride hard or in varied conditions, this Bel-Ray oil is an excellent choice. Part number 99160-B4LW.