Boat owners, this Sierra oil filter is built specifically for marine environments and it shows in the quality! The epoxy coating provides serious corrosion resistance, which is crucial when you're dealing with saltwater and harsh conditions. The anti-drain back valve is a smart feature that prevents oil from draining out when the engine's off, ensuring proper lubrication at startup. The heavy-wall steel canister is tough enough to handle marine engine demands, and the high-efficiency filter media does an excellent job trapping contaminants without restricting flow. With thread specs of 13/16x16 NPT, it fits various GM engines and other compatible applications. Sierra has been making marine parts for 50 years, and their experience really shows in this filter's design and construction. It meets or exceeds OEM specifications, so you're getting quality that matches what came with your engine originally. Whether you're doing routine maintenance or addressing specific filtration needs, this filter delivers reliable performance that protects your investment. The peace of mind knowing you have proper filtration in marine conditions is worth every penny. Definitely recommended for anyone who takes their boat maintenance seriously!