The new plastic Cerastus kits from GeeDubz are nice.

The problem is that their Cerastus upper arms are not compatible with their injection-molded Questoris and Dominus upper arms. You can't swap weapon arms.

A missed chance at intra-line modularity, in my opinion.

Likewise, folks who bought my Cervantes weapons to fit to factory kits found the parts didn't quite fit, even though they usually fit on other Factory kits.

These solve that problem.

Here are upper arms that enable you to use my line of Project Cervantes weapons on GeeDubz factory Cerastus kits. If you magnetize at the elbow with 12mm x 3mm magnets already, these are ready for you to print out and swap those existing weapons with just the addition of a magnet (remember your polarities).