Fencing Clamp Anti Tamper Spanner Tool | Male 3 Pin TypeThis tool is designed to be used with security fence fittings. If you are using heras fencing on site with the 3 pin male fixing style security nuts, then this tool is the best one for the job! The Right Tool For The Job There is nothing more frustrating than not having the right tool for the job. Below we have put together a quick look at each of the tools we have on offer and which security type nut it is suited to.