import Divider from '@mui/material/Divider';
import { Divider as MyDivider } from '@mui/material';

<Divider className="test" sx={{
  opacity: "0.6"
}} />;
<MyDivider className="test" sx={{
  opacity: "0.6"
}} />;
<Divider className="test" sx={{
  opacity: "0.6"
}} />;
<MyDivider className="test" sx={{
  opacity: "0.6"
}} />;
<Divider className="test" sx={{
  opacity: "0.6"
}} />;
<MyDivider className="test" sx={{
  opacity: "0.6"
}} />;
<Divider sx={{ opacity: '0.7' }} />;
<MyDivider
  sx={{
    bgcolor: 'black',
    opacity: "0.6"
  }} />;
