NSI Polaris Insul-Tap Connector, for Two Wires and in-Line Splicer/Reducer, ISR Series, 250-6 AWG Wire Range, 4.00" x 1.19" x 1.90", Pack of 4: Screw Terminals: Amazon.com: Industrial & Scientific
Polaris IPL3/0-3 Insulated Multi Tap Insulated Wire Connector-NEW | eBay
Amazon.com: NSI Polaris IT-350 6 AWG to 350 MCM 600V, Max 90C, Insulated Cable Connector 2 PORT : Industrial & Scientific