This guide is a solution to a clumsy and time consuming problem: getting the service wire through the wall or floor. Place the guide through a 3/8 hole. The tapered end helps you locate the hole on the opposite side. The flared end prevents the guide from pulling through the wall. After the cable is well through the wall, pull the guide back: a slit is provided in the guide to remove it from the wire. The highly visible, fluorescent orange tubing is firm enough to find its way through insulation. 20 In length. Five per package.