They're made of the same ABS plastic (or in the case of transparent parts, polycarbonate plastic) as any joint pieces before them. The design is what's sturdier, not the material.None of mine have even showed any sign of breaking. Pity the same can't be said of the Y-joints in my Jetbug set, which was from an early production run and thus used the 2008-2010 style of joints. Same, to both.