Shell PANOLIN S4 Stern Tube Fluid EAL 100 is a non-emulsifying synthetic fluid specifically developed for use in stern tubes. Manufactured from fully saturated esters, Shell PANOLIN S4 Stern Tube Fluid EAL 100 is designed to offer excellent lubrication performance whilst also being readily biodegradable with low toxicity. Shell PANOLIN S4 Stern Tube Fluid EAL 100 is an Environmentally Acceptable Lubricant (EAL) and holds the EU Ecolabel.