pieces. The wire hook which comes with many punch down tools can also be used to remove wire pieces. A new wire inserted over an existing insulation remnant may be unreliable, as the 110 IDC was designed to hold only a single wire per contact. For testing it is more difficult to reliably connect to a working circuit on a 110 block than on older style blocks. The circuit must be broken, or insulation displacing contacts may be used on jumper wires. Repeated use of insulation displacing contacts may lead to a difficult-to-locate broken or intermittently-failing jumper wire. See also 66 block Telecommunications Industry Association Electronic Industries Alliance Electrical wiring Krone LSA-PLUS References Telephony equipment Local loop Networking hardware