Medieval Sri Lanka [solved]

Hi, i would like to ask you some help to understand the ruler of this medieval Sri Lanka coin.
To my eyes they look all the same, maybe i must check some particular sign.
Thank you for your help.

w= 4,41g d=19mm

See http://coins.lakdiva.org/medievallanka/identify.html and http://coins.lakdiva.org/medievallanka/1236_1271_parakramabahu~ii.html

Yes, it takes some hunting around in different sites to match the writing. Your coin is a copper kahavanu from Parakrama Bahu II, 1236-1271 AD.

https://www.vcoins.com/en/stores/coinindia/36/product/sri_lanka_singhalese_kingdom_parakrama_bahu_ii_123671_ae_kahavanu/671201/Default.aspx

Thank you, now everything is clear.

https://sirimunasiha.wordpress.com/about/the-coins-of-pandyan-and-colas-found-in-srilanka/
http://coins.lakdiva.org/medievallanka/polonnaruva.html
https://en.wikipedia.org/wiki/Polonnaruwa_period
http://coins.lakdiva.org/medievallanka/dambadeniya.html
https://en.wikipedia.org/wiki/Kingdom_of_Dambadeniya

Thanks for all the references, PetrusAscanus. These will be helpful to ID Sri Lankan copper kahavanus in future.