Ladder Leveler, Ladder Tool Extension Ladder, Ladder Leveling Tool, Stair Ladder with Storag Stable Platform for All Surfaces and Uneven Ground - Amazon.com
Tanfix Foldable | Heavy-Duty Ladder Extender, High Strength Steel Material Design Ladder Extension for Stairs, with Non-Slip mat, 9.25-15.5" Adjustable Height Range : Amazon.ca: Tools & Home Improvement
ProVisionTools Demonstration - YouTube
Industrial Products ProVisionTools, Inc. PiViT LadderTool Extension Ladder, Leveling Tool, and Stable Platform for All Surfaces (2 Pack) - Amazon.com
PiViT LadderTool | Ladder Leveler - ProVisionTools, Inc.