6.A.3.Switching devices as follows:

a. Cold-cathode tubes, whether gas filled or not, operating similarly to a spark gap, having all of the following characteristics:
1. Containing three or more electrodes;
2. Anode peak voltage rating of 2.5 kV or more;
3. Anode peak current rating of 100 A or more; and
4. Anode delay time of 10 µs or less;
Note: Item 6.A.3.a. includes gas krytron tubes and vacuum sprytron tubes.
b. Triggered spark-gaps having both of the following characteristics:
1. Anode delay time of 15 µs or less; and
2. Rated for a peak current of 500 A or more;
c. Modules or assemblies with a fast switching function having all of the following characteristics:
1. Anode peak voltage rating greater than 2 kV;
2. Anode peak current rating of 500 A or more; and
3. Turn-on time of 1 µs or less.