Parts - These are mostly t-spline parts for your library.  They include common bridges, filler blocks, or channel bars.  It also includes a ruler for rendering with objects, and a few hinges.  The tspline parts are easily adaptable for your needs.  Even the simple ones are easy and ready to use without you having to start from scratch. Get them now while you can. 

These parts are mainly used in building rings from the shanks in the "Shanks" pack.  Don't let the simple shapes fool you.  They are very powerful when combined with shanks to build your rings.