Attwood Stainless Steel Gas Spring Attwood Stainless Steel Gas Springs feature a stainless steel shell and rod to ensure corrosion-resistance. All Attwood stainless steel springs come with high-strength, corrosion-proof composite end fittings. All springs pass ASTM B117, Attwood salt spray and a 30,000 cycle lifecycle test. New clip-less design End fitting type for all sizes 10mm socket Size Chart 8mm Rod x 18mm Cylinder Part Extended Length Compressed Length Stroke Standard Output Force ST3020