Jumbo Holiday Thistle Sack Red. Now with the holiday Nyjer socks you can make your yard feel like Christmas all year around or just put them up over the holidays. These holiday themed socks will really have your yard glistening in the dead of winter and will keep your local birds fed. The socks feature a Velcro seal at the top for easy access and serves as a reliable seal to prevent spillage. Made of nylon.