A back magnetic lens cap is a handy addition to sandwich your filters safely between the two caps. If you need a front cap please check out this link.
To use the magnetic lens cap on your lenses when the filters are not installed you will need to use the adapter ring that comes with the kits, or purchase an additional magnetic adapter ring in the correct sizing.
If you need to purchase a cap in a size not listed, please enquire via the Contact page for availability.