4 AWG 3/8” 2-Hole Copper Long Lug with Peep Hole – Gray
https://nsiindustries.com/product/4-awg-3-8-2-hole-copper-long-lug-with-peep-hole-gray-2/
The POLARIS compression design creates a permanent, vibration-resistant connection that you can rely on with low contact resistance. Suitable for a wide range of applications, including power distribution, grounding and data transmission.