I use a string of 15 of the Hosfelt/GE poly snubbers, 0.33uf -at- 2000V. Probably not bulletproof with a 15/90 NST but I have had no problems. The caps are mounted on perf board and the bleeders mounted on the opposite side of the board. I just bot another 40 of them at $1.75 ea. Best holiday wishes to all, Ralph Zekelman