Jim told me they can go down to as low as 250v. I asked that question about some NOS Vitamin Q caps I found. I actually had to buy four of each value 0.047uf (630v) and 0.001uf (400v). If you are interested in these caps--since I only need two of each value, I can sell you the two extras that I have. They are arriving from China, and hopefully will arrrive this week.
Just let me know,
Dan