The Sporty's clock has that annoying "Not for certified aircraft, for EXPERIMENTAL aircraft only" disclaimer.
It's a CLOCK for crying out loud!!!
It boggles the mind. The "experimental" guys can fly their airplanes in the same airspace, over the same cities and population, in the same weather as we do. BUT, they can do it with a $100 clock, and we have to use a $300 clock.