This shako plate for sun observation uses a "JIS standard, flash intensity No. 13" filter that completely blocks rays that are harmful to the eyes (Ultraviolet, infrared, glare light).
Specifications
Filter used: JIS T 8141, Absorbance No. 13, Size: 46 x 101 mm
Filter frame: ABS resin (red) with neck strap, size 170 x 74 mm