Piston circlips

Hi all,
I have a 62.2 'Asso Werke' 3 ring piston for my TV175 that i have misplaced the circlips for
,should they be the flat 'Seeger' type,or the 'wire' type??,ive tried looking (even with a magnifying glass) at the profile of the slots,but still cant make out which it should be!,anyone in the definite know?? 
I have a 62.2 'Asso Werke' 3 ring piston for my TV175 that i have misplaced the circlips for

