The Urth 86-37mm Adapter Ring for 100mm Square Filter Holder is made of aluminium and is used to mount the 100mm Square Filter Holder from Urth on lenses with a 37mm front filter thread.
Urth 67-39mm Adapter Ring for 75mm Square Filter Holder
Urth 67mm Magnetic Adapter Ring
Urth Lens Adapter Praktica B Lens to Sony E Mount
Urth Lens Adapter M42 Lens to Nikon Z Mount
Urth Lens Adapter M42 Lens to Leica L Mount
Cokin P467 67mm P Series Adapter Ring
