cam-K designed and developed the Safety Ladder Lock. The only of its kind. It is a safety tool that goes on the top of an extention ladder.Its universal and fits most size ladders. it is a multi tool.Customers- consumer and commercial users. Please watch the 5 Min video at cam-K.com to better understand how the product works and the potential.Thank you for your time Barbara as I know it is at a premium.Patent Pending