IDC Butt Connector The UR2/UR2-D solvent resistant connectors accept two or three solid copper conductors that can be of different wire gauges, for butt splicing. The UR2 connectors are filled with a sealant to provide moisture resistance. WARNING: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.