https://www.ebay.com/sch/i.html?_nkw=3M+Auto+Darkening+Filter+1+8+X+3+7+Shades+5+8+13&_sacat=0&_dmd=2

3M Auto Darkening Filter, 1.8' X 3.7', Shades 5, 8-13

Regular price
$311.00
Sale price
$219.00

Auto Darkening Filter, 1.8 In. x 3.7 In, Shades 5, 8-13, For Use With 4EFL4, 4EFL5, or 4EFL6, Includes (2) CR2032 Batteries