Urth 100mm Lightweight Durable and Compact Square Filter Holder for 100mm x 2mm Square FilterUrth 100mm Square Filter Holder is consciously designed for the brand's 100mm Square Filter range. It can hold up to two 100 mm square filters (2 mm thick) plus an adjustable polarizing filter. Lightweight Filter Holder The square Holder System is made from magnalium and is durable, lightweight and compact. It can hold up to two 100 mm wide square filters at a time. You can also use Urth brand's CPL Polarizing filter with this adapter for adjustable