62d8f06818b73df84e2dbdaaProgress Universal X-Ray Film Mounts Window - Box of 1000https://www.gunz.com.au/s/62cbbdfb14348300a8ff835e/62d8f06b18b73df84e2dbddc/pro1000.jpg
A continuous roll of 1000 windows 1.75 x 1.75 inches wide for storing film negatives.