Solar filters for binoculars

In working through getting our supplies for the solar eclipse trip, I was thinking about getting a pair of solar binoculars to match the kid’s smaller solar binoculars.  But, decided to pass since I hope to get a solar telescope.  But, than as I was skimming one of the eclipse books I purchased, I saw a section on solar filters.  I knew they existed for telescopes but found out they existed for binoculars too. 

So, I did some research but the prices were very high.  Some were similar prices to dedicated solar binoculars.  But, then I found out Rainbow Symphony sold film solar filters instead of the more expensive glass filters.  The price was around $20 though would need two.  I added it to my purchase list.