As you see on this page not only are there swing and slide there are many variations on them, Large and Heavy,Short and Tall,Solid,light weight,etc. so there is no standard and there are many factors to picking the right operator also, such as if the gate is a long swing say 16feet plus and tall say 7 feet with pickets at 4" and the gate is in the open exposed to the wind like on a ranch entrance then this would pose a major wind stress on the operation of this gate and would require a large operator than a lighter more protected gate like an entrance right off a street with houses and trees to somewhat block the wind. so when deciding which operator to buy and install on your property thats the first factor that I look at. No stop let me back up the first factor should be building and correctly installing a high quality gate because that gate must always swing or roll smooth and consistant, the operator can't see or feel a rusted or bound up hing are a bad roller or all the things that go along with a poorly built or installed gate system. with that said moving on to the operator a high end operator is not only constructed stronger because the larger motor and to handle the heavyer gates but also the incresed cycle demand, this will give you much longer trouble free operation. aside from that you also have the ability to add many accessories to them such as telephone entry systems,with security and camers,exit and safety loops.