Sierra's 18-5002 Tune Up Kit is designed for use with select Johnson/Evinrude 18 HP, 20 HP, 25 HP, 28 HP, 33 HP, and 40 HP outboard engines. The kit contains (2) Sierra 18-5156 Contact Sets and (2) Sierra 18-5205 Condensers. The kit is interchangeable with GLM 72820 and Johnson/Evinrude Outboard 0172523. Each Sierra product meets or exceeds the original equipment part it replaces. Fit specific, check part numbers to ensure proper fit.