Lee Big Stopper (100x100mm) brand_ROR with very clean glass and

with very clean glass and good function

It features a trick hybrid electro-mechanical shutter with speeds from 1s to 1/4000s (plus Bulb) and aperture-priority autoexposure

The box claims that this is for the Spectra System and that it "can also be used with Polaroid Impulse Cameras

so keep it in mind

Lee Big Stopper (100x100mm) brand_ROR with very clean glass andThe Lee Big Stopper is a 10 stop ND filter designed to fit a 100x100mm Lee filter holder or compatible. Neutral, high quality glass and a foam pad to prevent light leaks a well designed filter for long exposures. Requires a compatible filter holder (not included). In excellent condition, with carrying tin.