This original ECU Harness Coupling Nut is a replacement for any Mercury Racing / Mercury Marine / Mariner 150, 175, 200, 225, 260 ROS, 280, 300 Drag, S3000, and F1; including 2.0, 2.4, 2.5 Liter 2-Stroke V6 outboards.
Fits both front Laser and ROS side injected motors. 
 
Our connector coupling ring nut snaps into place on all the 16-pin EFI ECU Harness manufactured, to replace your original nut, which tends to get brittle and break over time.
Instructions: 1) remove old nut, ensure you have the new nut in the correct orientation. 2) Once evenly in place, snap into place. 3) It becomes somewhat permanently attached until you break it off. 4) Replace if damaged in the future, have an extra nut on hand to ensure stable ECU connection. 
 
UL Rated and RoHS Compliant.