Werner Aluminum 21.5-in Stabilizer For Ladders in the Ladder & Scaffolding Accessories department at Lowes.com
Tie Down Roof Zone 19-Inch Stand-Off Extension Ladder Stabilizer - Ladder Standoff for Added Stability and Safety - Prevents Gutter Damage - Amazon.com
Roof Zone Extension Ladder Stabilizer - Walmart.com
Werner AC78 - Quick Click Ladder Standoff / Stabilizer - Fit On Extension Ladder | eBay
Werner D1200-2 20-ft Aluminum Type 2-225-lb Load Capacity Extension Ladder in the Extension Ladders department at Lowes.com