The right-handed sense of a helix traces out a clockwise rotation moving away from the observer; the left-handed sense of a helix traces out a counterclockwise rotation moving away from the observer, e.g. the ...${\mathrm{TG}}^{+}$ ${\mathrm{TG}}^{+}$ ${\mathrm{TG}}^{+}$ … helix of isotactic poly(propylene) is left-handed.