Two upside down 'u' shaped crafts, similar to a horse shoe shape. my husband, son, and i were sitting outside when we noticed, what we thought was a balloon at first, floating from the tree line. as it got closer we realized it was bigger then a balloon, about the size of an adult person. he thought it was someone in a glider suit. the object seemed to alternate from a black to reflective silver surface. it was a horizontal upside down 'u' and the 'legs' of the 'u' would sort of 'kick' changing from the black to silver, as if you were in a pool and pedaling slowly to stay afloat. we then noticed a 2nd one, following the same exact flight path. we live by 2 airports, usually a lot of air traffic, when objects flew through, we realized, there were no planes in the air in any direction which is unusual.