#resImage_275 {
    display:block;
    overflow:hidden;
    background-image:url('http://www.cntech.co.uk/assets/images/h/contact-test-ecx6myxa649s82a.jpg');
    background-repeat:no-repeat;
    background-position:center center;
    width:100%;
    background-size: cover;
    height:580px;
}
@media screen and (min-width:700px){
    #resImage_275 {
        background-image:url('http://www.cntech.co.uk/assets/images/v/contact-test-y1vkd3c8nbvvjhc.jpg');
        height:465px;
    }
}
@media screen and (min-width:980px){
    #resImage_275 {
        background-image:url('http://www.cntech.co.uk/assets/images/g/contact-test-14wm674jbph5epx.jpg');
        height:465px;
    }
}
@media screen and (min-width:1400px){
    #resImage_275 {
        background-image:url('http://www.cntech.co.uk/assets/images/g/contact-test-14wm674jbph5epx.jpg');
        height:465px;
    }
}