Popular low-cost earmuff style flush-tester.  Fits most brands with side water intakes in lower unit.  Allows for attachment of garden hose water supply for flushing and test-running.

Flushing attachment. Screws into the threaded hole on Mercs with a removable METAL flush plug. NOT recommended for running engine out of water.

Mercury's unique design for earmuff style flushing-test attachment.  Has oversize cups and a retaining pin that passes through the gearcase openings on housings with side water intakes to prevent  slipping out of place.  Allows for attachment of garden hose water supply for flushing and test-running.

Fits Mercury, Mariner 4-15 hp 2 cycle and 9.9/15hp Four Stroke engines with standard gearcase.