A. Male: Two-prong Fuel Tank quick-connector fitting for Mercury engines. 1/4'' NPT. Brass construction. -521-052-00B. Female: Two-prong Fuel Line quick-connector fitting for Mercury engines. 3/8'' barb. Resin construction. -521-056-00C. Male: Fuel Tank quick-connector fitting for Mercury engines. 3/8''barb. Cast aluminum construction. -4...