Polaris IPLMD500-10 500 Mcm – 4 Awg Polaris Insulated Multi-Tap Conn 10 Port (Dual Sided Entry & Mountable)
https://nsiindustries.com/product/10-port-black-mountable-pre-insulated-connector-500-mcm-4-awg/
Polaris Black Multi-Tap Mountable Connectors form secure connections between multiple conductors with a rounded design and UV-resistant insulation coating. Installs with a hex key and torque wrench, with no need for cover and taping.