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The sign accompanying the engine. It reads

RL10 Engine

Pratt & Whitney developed the RL10 engine in 1959. Since the first successful RL10 powered Centaur rocket flight in 1963, more than 175 RL10s have operated in space without a failure.

Thrust:	6,500 lb
Fuel/Oxidizer:	Liquid hydrogen/liquid oxygen
Mixture Ratio:	5:1
Specific impulse:	444.4 sec

This is a rather old sign; Pratt & Whitney issued a press release in April of 2009 marking the launch of the 400th RL10 engine, and as of November 2023, that number had reached 522.