Any of these should be fine but I think there is a specific slightly different part# for the EJ20K but I'm not 100% sure:
Photo
Standard BKR6ES
6364
.030
V-Power BKR6E
6962
.030
G-Power BKR6EGP
7092
.030
Laser Platinum PFR6G * #
4793
.030
Iridium IX BKR6EIX
6418
.030