This is a HLC (Homer Laughlin) platter.
The platter is in the "Swing Eggshell" pattern with yellow rims, and a Colonial kitchen pattern on eggshell. On the back, it has the production number D40N5 (April 1940 Newell W.V.).
It measures about 13" long and 10.5" wide.
The platter is in good pre-owned condition.