The cylinders contain low-friction nitrile seals and are factory lubricated with PTFE impregnated grease. The L Series precision machined components and selflubricating bearings offer long life and continued low-friction operation. The cylinder's smooth body exterior (no bolt together or retaining wire hole access) means no dirt or grease traps. The L Series are constructed of thick-walled, anodized aluminum housing and caps with chrome-plated 303 stainless-steel rods riding in self-lubricating bronze bearings. Hardened 302 stainless-steel retaining wires are used for assembly. The cylinder's bore and rod sizes are metric in design and mounting and porting are offered in inch or metric.