The model 103 Tag Line from Solinst Canada is designed for use in monitoring well installation and uses a weight attached to marked stainless steel cable. It can be used to measure the depth to the top of backfill sand or bentonite layers during completion of a well and to measure the depth to the bottom of a well. The Tag Line uses polyethylene-coated 1⁄16-inch stranded stainless steel wireline with a minimum break strength of 270 pounds. The weight can be clipped on and off the cable, and low-profile markings are bonded in place every 5 feet, with more markings available. Solinst Canada