Detector Loop - Saw Cut Kit (100 ft) - HME 333G012
HME Retro-Fit Loop, Saw Cut Kit, P/N: 333G012 / 400G766A
This is what's used when the lane has already been poured and you need to install a loop for a new headset or timer system. These are also used to replace failed loops.
Having a pre-fab loop installed by the general contractor during construction is always the best option.
Retro-Fit Saw Cut Loop Installation Instructions