I have their aluminum pulley and it works great. The plastic stock one will chip within one month of usage. This is an example of pure stupidity on the part of business profit margins... eventually, people will lose faith in the brand due to cutting corners that should not be cut. There is zero play in bolts and no deformation of the pulley's roundness at all. Super smooth operation with zero vibrations after a few months of usage.
Back to the oil cap... I am sure they got the center locking tabs right, but what I truly concerned about are the three nipples and the center nub that push the spring loaded center cage clip upwards upon installing the center cage. If those three nipples and the center nub are present, then this is a great upgrade to the plastic unit.