Hello bhsatish,
By reading the descriptions any sony ericsson w810i mobile phone listing you can find the necessary information and in your case
sony ericsson w810i is compatible with
'Memory Stick PRO Duo'. Click
here to buy
'Memory Stick PRO Duo' and
here to buy
'HPM-70 handsfree' :-).
When you find an item, read the item description carefully. If you have any questions that aren't answered in the item's description such as originality, warranty etc, you can ask the seller about the item by clicking the "Ask seller a question" link.
Hope the above information was useful :-).
Keep posting!!
Regards,
Indraneel