Cosmo Ferrites Limited : Ferrite E Core manufatures, E cores were one of the first ferrite cores to be manufactured, being derived from their respective steel lamination size. Cosmo Ferrites's range reflects a selection of cores that have become, over many years, worldwide standards through continued use.E Cores are an ideal choice as they are less expensive than POT Cores. E cores are particularly suitable for power transformers and filters at low frequencies.
The E cores are lightweight, easy to install, and quite efficient. We offer these cores available in different sizes with applications like power and telecom inductors, broadband, inverter transformers, and more.

https://www.cosmoferrites.com/product-size/e-cores