H&Y Filters K-Series 100x100mm MRC White Promist 1/8 Filter with Frame (HD Optical Glass) Hadley Small Pro Camera Bags At the top they have

At the top they have top-flap that secures with two simple press-studs

it is also compatible with regular spin-on filters

2455: illuminated area: 42

CHAMONIX FH88 Film Holder 8x8 (Wooden) with Carbon Fibre Dark Slide - Sheet Film

This band extends in both vertical directions which tapers to approximately a 1

H&Y Filters K-Series 100x100mm MRC White Promist 1/8 Filter with Frame (HD Optical Glass) Hadley Small Pro Camera Bags At the top they haveH&Y Filters 100x100mm K Series MCR White Promist Filter (1 8) w Quick Release Magnetic Filter Frame Key Features For 100mm K Series Filter Holder White Promist (1 8) Filter 9 Layer Multi Coating, Optical Glass Quick Release Magnetic Filter Frame Magnetically Mounts on Holder Fast Use of Filter on Holder The H&Y K Series 100x100mm MRC Mist White Filter is crafted to soften light and reduce harsh contrasts while preserving superior image clarity. This