How Do I Get Attachment File From Sharepoint List Using Client Object Model

$(window).load(function () {
        SP.SOD.executeFunc('sp.js', 'SP.ClientContext', ReadListItem2);

    });

    function ReadListItem2() {
        var url = location.protocol + "//" + location.host + L_Menu_BaseUrl
        var context = new SP.ClientContext(url + '/');
        var listTitle = "Apps";
        var _List = context.get_web().get_lists().getByTitle(listTitle);
        var camlQuery = SP.CamlQuery.createAllItemsQuery();
        this.listItems = _List.getItems(camlQuery);
        context.load(listItems);
        context.executeQueryAsync(ReadListItemSucceeded2, ReadListItemFailed2);

    }

    function ReadListItemSucceeded2(sender, args) {
        var itemsString = '';
        var enumerator = listItems.getEnumerator();
        $("#appsImagesout").append("<ul>");
        while (enumerator.moveNext()) {
            var listItem = enumerator.get_current();            
            
            var _url = listItem.get_item("URL").get_url();
            fr = new FileReader();

            var _att = listItem.Attachments;

            if (_url != '' && typeof _url != 'undefined') {

                $("#appsImagesout").append("<li><a target='blank' href='" +  _url + "'><img width='50px' height='50px' src='" + _att + "' style='padding-left:10px;'/><a></li>");
          
            }
            $("#appsImagesout").append("</ul>");
        }
    }

    function ReadListItemFailed2(sender, args) {
        alert('Request failed. ' + args.get_message() + '\n' + args.get_stackTrace());
    }