Plumbing BobThese are laser cut out of 1 4" steel and powdercoated grey. We used a bright orange braided string with a 20LB magnet washer attached to the end. This allows the string to be wound up and stuck in place securely between poles. We went with flat steel on this one which is heavy enough to be resistant to windy days but also lay flat in your pocket. This plumb bob can comfortably be carried throughout the day.