The circumference of the silicone bands are purposely slightly larger than the channels into which they fit, because there has to be enough flex in the bands such that when the lid is closed/tabs locked, the downward pressure causes the bands to “bulge” outwards to create the leakproof seal around each compartment. If the bands fit just right/snug, then “leakproof” is not guaranteed (because there is no “bulging of the bands” to form the proper seal). Therefore, it is important that, after removing/washing the bands, they have to be “completely tucked back into” their respective channels.