10 tread GRP Glass Fibre Trade Swingback step ladders, every electrician should have a set of. Ideal for short duration work, in a spark risk environment. The combination of super-strong C-section glass fibre stiles & reinforced aluminium treads gives you a step that's electrically insulated to 35, 000 volts. A durable yet lightweight & easy to handle step. Closed Height (m) 2.55. Open Height (m) 2.5 Rungs/ Treads 10 Material Glass Fibre. Usage Type Heavy Duty. Warranty 5-Year. Standard EN131 Professional. Open Depth (m) 1.94. Weight (kg) 12