The piece of PVC, the poly(vinyl chloride). PVC is used for flooring and siding. PVC is also used for squeeze bottles in the laboratory. Note that the polymerization of chloroethene creates chiral centers at the chlorine-substituted C-atoms. The model shown reflects that these centers of chirality can have either configuration in a random fashion. The model contains an all-trans backbone of C-C bonds and the polymer appears rather "straight". Of course, actual PVC can also realize some gauche conformations resulting more winding polymer strings.