Genie 36255W Garage Door Opener with 1/2-Hpc Dc Chain Dc Motor Is A Lighter Weight Providing Quiet, Smooth Operation & Soft Start & Soft Stop Provides 1-touch Limit Setting Meaning Fewer Trips Up The Ladder Commercial Grade Chain Drive System Is Durable & Provides A Longer, More Reliable Life Comprehensive Safe-t-beam System Meets Or Exceeds All Ulf, State, Federal & CA Regulations & Incorporates An Auto Reversing System & Diagnostics Genie Intellicode Technology Prevents Unauthorized Persons From Opening Garage Door By Automatically Changing The Access Code Every Time It's Used