This full color 4" x 6" postcard from the Trinity College Library in Dublin, Ireland, features the "Brian Boru" harp which is on display there.
The back of the postcard has plenty of room for the mailing address and your personal message.
The information on the back of the postcard reads: This 15th or 16th century harp is the oldest surviving Irish harp and has been erroneously associated with Brian Boru, high King of Ireland (died 1014). It is made of willow and has 29 strings.
You can purchase this postcard individually, or in packs of 6 postcards.