Flash suggestion

[mukul]

Hi all,

I just stumbled upon this Flash.
http://www.ebay.in/itm/321484478567?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
Ref:
http://www.cameramanuals.org/flashes_meters/sunpak_522.pdf
http://www.lowcost4dslr.com/tests/flash/12-sunpak522
http://www.pentaxforums.com/forums/125-flashes-lighting-studio/248965-sunpak-autothyristor-522-a.html

Though I'm not in a dire need of a flash yet (do not use the popup flash often even) I'm thinking to buy it.
Reasons:
[list type=decimal]
[*]I sometimes do little bit of macro with extension tube with following setup, and when I go near 1:1 or more the setup goes so close blocks most of the light.
[*]It is working in all manual, and damn cheap @2,500 INR or $41 USD.
[*]Any good flash will cost me above $150 USD and I can not spend that amount now or near future
[/list]

Please let me know your thoughts.
In terms of voltage will this be safe to use on Canon EOS 600D?



My gear

• 600D
• Extention tubeset [AF]13mm, 20mm 36mm. I use them with 50mm or 200mm
• EF 50/1.8 Mk2
• Jupiter 200/4 m42 lens with focus confirm adapter, with all 3 ext tube it produces ~0.5 MM at great working distance
• A tripod
• 4-Way Macro Focusing Slide Rail, This adds good amount of shake in windy condition
• Cable release with timer function
• EFS 18-135 IS (first version, non STM)