Traditional scope flip covers require clearance for the cover to flip up (or to the side). This is problem if you have two optics, such as a red dot and a magnifier, mounted closely together. Butler Creek have solved this problem with the Sidewinder cover that rotates to the side and then flips to the side. You can see it demonstrated in the video below.
The Sidewinder Flip Cover will be available to fit 30mm eyepiece lenses and 38mm objective lenses. It will work on scopes such as the Aimpoint CompM2, Bushnell TRS-32, Burris 332 EP and Sightmark Tactical Red Dot. The MSRP will be $21.95 later this month.