Product of Telescopes

The product of two Telescopes $\Gamma,\Delta$ is given by their concatenation. This may seem somewhat backwards, but recall that Morphisms of Telescopes are given by Weakenings; the projections $\pi_{0}:\Gamma\times\Delta\to\Gamma$, $\pi_{1}:\Gamma\times\Delta\to\Delta$ perform the evident weakenings, and the universal property ensures that there isn't "extra junk".