No need to remove the Main Adapter ring and C-PL after use, Leave it mounted and the cap will protect it from scratches and dust.
No need to remove your 67mm adaptor ring
Works with and without the C-PL
Designed for the NiSi M75 holder
Description
The NiSi M75 Protection Lens Cap is designed to attach to a NiSi M75 75mm holder's 67mm adapter ring when the kit's filter holder is removed. While in use, this lens cap can protect a NiSi mm Circular Polariser Filter installed on that 72mm adapter ring while the adapter ring remains on a lens.