To whom it may concern:
I am writing this letter to invite our parents (name and brithdays) to visit us in (country) this coming (month) for aperiod of 6 months.
It goes without saying that we will cover all expenses duringTheir visit in (country), which includes international air tickets, local transportation, accmodations, medical
insurances and all other related expenses.
Your favourable consideration regarding their visa Applications will be highly appreciated. If you have any question regarding this matter, please kindly contact me at the address above
Sincerely,
XXX