Western-Cullen-Hayes Model SA, hinged derails significantly reduce the lifting effort required to move the derail on or off the rail. These derails are fabricated fro steel and are sized to ensure proper fit on today's most popular rail sections. Model SA derails come in left or right hand versions. We also make a two way SA, the SA-XS, that is larger than our traditional bidirectional, hinged derail. All of our hinged style derails incorporate a hand grip for ease of lifting . Installation requirements for the SA style derails are the same as all other WesternCullen-Hayes derails.