Teknetics 5COIL-T2 5 DD Coil The new Teknetics Searchcoils have been upgraded with the latest technology so that you can best take advantage of everything that your Teknetics Metal Detector has to offer. In general, larger searchcoils will give better depth with larger targets and better ground coverage. However, sensitivity to smaller objects may be sacrificed. Smaller searchcoils will offer greater sensitivity to smaller objects and improved target separation in trashy soil. All Teknetics Searchcoils are electro-statically shielded and waterproof.