#resImage_247 {
    display:block;
    overflow:hidden;
    background-image:url('https://www.tjelectrical.co.uk/assets/images/a/cctv-7c81606a.jpg');
    background-repeat:no-repeat;
    background-position:center center;
        width:100%;
    background-size: cover;
        height:450px;
}
@media screen and (min-width:700px){
    #resImage_247 {
        background-image:url('https://www.tjelectrical.co.uk/assets/images/f/cctv-8de05908.jpg');
                height:375px;
    }
}
@media screen and (min-width:980px){
    #resImage_247 {
        background-image:url('https://www.tjelectrical.co.uk/assets/images/9/cctv-edeec0b0.jpg');
                height:470px;
    }
}
@media screen and (min-width:1400px){
    #resImage_247 {
        background-image:url('https://www.tjelectrical.co.uk/assets/images/9/cctv-edeec0b0.jpg');
                height:470px;
    }
}