The Ihagee looks as if it's the same holder as my Ihagee (which was a fairly common holder, shared by several makes). Most of them don't have any particular identifying names or marks, you'll just have to go by auction photographs of them or ask the vendor the size. The thin lipped ones (as you have) vary in length and how snugly they fit down in the slot. It's really just trial and error until you find enough to get you going. Best of luck finding film inserts for them - most of them seem to have got chucked out or lost.