Large high voltage flyback transformer type JCM 6174V-8005 can produce large arcs. Great for high voltage experimentations. Check the Internet for various easy to build circuits to drive this flyback. Has 11 pins on the bottom, 2 flexible red & white leads plus a 21" long high voltage lead with CRT KV connector. This unit has 2 adjustable controls on the side. Size about 2.7" tall (excluding pins and top high voltage fitting) x 2.4" x 2.1". Brand new, but no specs, hookup info or other data.
DISCLAIMER: You should not buy this unless you are familiar with working with high voltages and you should be careful to take all safety precautions with using this item.