How to Pass Session with mutiple value from one page to another page

I selected  mutiple values  into Session band that is 

Session["band"] =C,8357,8358 on Default.aspx

Now i redirected the Default.aspx to Site.aspx

only the first value of Session["band"]  appears that is 

Session["band"]  = Session["band"]

how do i get the mutiple values of Session["band"] in  Site.aspx.

Please help

protected void ImageButton4_Click(object sender, EventArgs e)
{
    List<string> id = new List<string>();

    foreach (GridViewRow row in gvDetails.Rows)
    {
        CheckBox chkdelete = (CheckBox)row.FindControl("chkSelect");
        if (chkdelete.Checked)
        {
            id.Add(row.Cells[1].Text);
        }
    }
    Session["id"] = id;

    Response.Redirect("rrrr.aspx");
}


rrr.aspx


protected void Page_Load(object sender, EventArgs e)
{
    List<string> id = (List<string>)Session["id"];
    //Response.Write(Session["id"]);
    Response.Write(id);
    // Response.Write(Session["Time1"].ToString());
}