This is the COLT - Clamp On Line Tension meter with Bluetooth output to free iOS and Android app from Crosby Straightpoint. The COLT is the perfect guy wire meter and clamp on tension meter for wire rope up to 1" in diameter. 

Recommend by Crown Castle, it allows the operator to measure load on a pre-tensioned wire ropes such as guy lines or elevator cables up to 1" diameter & 11,000lbs and then, using the COLT app, record and log load data along with GPS co-ordinates and local weather conditions from your smart phone. 

Unique sheave design means wire ropes from 3/16" to 1" diameter can all be measured without the need to change sheaves. Unlimited wire rope database - over 160 are currently stored in the cloud database - view the current wire rope database here

The COLT is waterproof to IP67 or NEMA 6 and has been drop tested from 10 feet and retains accuracy making this the ideal tool for workers in the field checking line tensions. 

Supplied with a wire rope diameter gage and now including with calibration verification rod  allowing the user to check calibration accuracy in the field.