[Cokin P or M Type i.e. 84mm Wide Slot, as tested] Cromatek Matte Box with Bellows Extension

~ plus Hasselblad B50 & B60 Adapter Rings (to fix to the front of your lens, and so mount the matte box to the front of your lens)

All audio-visual items are wiped down during examination.

To insert a filter, open up the velcro-seals and to access the box which it keeps shut. Your filter will insert into the single slot within that box. 

The bellows are in excellent condition. The extension mechanism works just fine, it is loosened by turning the screw, before it is then extended.