Tupperware replacement seal #227 it says C on the tab. 

This lid/seal is in good used condition some scuff marks from use.  Some lids lay flat, some have some warping that does not affect how it fits.  Please see photos. 

It measures approximately 6 1/2" across.

If purchasing more than 1 lid, please contact me for combined shipping discount.

You get the next lid in the stack, so it may lay flat and it may not lay flat.