Lowepro Mini Trekker brand_Photographer's Formulary This SLR Magic Variable ND

This SLR Magic Variable ND Filter Mark II is specially designed to minimize the weird uneven vignetting that sometimes afflicts variable filters

built-in WiFi

This one has a decent amount of cosmetic wear and is missing a section of leatherette around the top of the viewing lens (see photo)

5L of working chemistry

Lowepro Mini Trekker brand_Photographer's Formulary This SLR Magic Variable NDThe Lowepro Mini Trekker isn't that mini: it's big enough to hold a reasonably sized camera setup. About the size of a "normal" school backpack, it features a padded compartment with dividers, a couple of front pockets, and provision to attach a tripod. Interior dimensions are approximately 12x30x36cm.