This is a version of the standard V-Lock insert that has a larger 6" mounting surface.
The picture shows the medium insert next to a standard 4" insert for comparison.
The Medium 2.5" High Bent Insert (new and limited availability) is bent at 2.5" rather that 1" above the point there it meets the base. This provides some additional clearance for situations where 1" does not place the application high enough. This reduces the mounting surface to 4.5"
There is a flat one and a bent one like the regular inserts and now a high bent as well.
These are not anodized.
Note: These replace the large 8" inserts which are discontinued