These simulators for mobile devices are based on the following @media calls and container sizes

/*******IPAD LANDSCAPE*****************/
@media all and (width: 1024px) {
    #container {width: 1024px}
}

/********IPAD PORTRAIT*****************/
@media all and (min-width: 601px) and (max-width: 768px) {
    #container {width: 768px}
}

/**********NARROW TABLETS***********/
@media all and (min-width: 481px) and (max-width: 600px) {
    #container {width: 480px}
}

/**********IPHONE4 LANDSCAPE***********/
@media all and (min-width: 321px) and (max-width: 480px) {
    #container {width: 480px}
}

/***********IPHONE PORTRAIT************/
@media all and (max-width: 320px) {
    #container {width: 320px}
}

Select a mobile simulator

Thumbnail of an iPad
iPad Landscape
Thumbnail of an iPad
iPad Portrait
Thumbnail of an iPhone
iPhone Landscape
Thumbnail of an iPhone
iPhone Portrait