Web lifelines are lightweight and commonly used for compact SRLs and harness-mounted PFLs. Wire-rope or steel-cable lifelines can provide increased abrasion resistance and may be offered in longer lengths or sealed units for demanding environments. However, metal lifelines may not be appropriate near electrical hazards. Consider sharp edges, welding, heat, moisture, chemicals, corrosion, electrical exposure, weight, and required length when choosing the lifeline material.