Polaris GL30048 CMP Lug Cu Short 300 MCM 1/2 Bolt
https://nsiindustries.com/product/polaris-gl30048-cmp-lug-cu-short-300-mcm-1-2-bolt/
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.