Longbow +3

Long Bow +3 is an enchanted weapon, which has a -2 THACo and a speed factor three units lower when it's compared to a normal Long Bow. This item appears in Baldur's Gate II: Throne of Bhaal and Baldur's Gate II: Enhanced Edition.

It can be bought from the Tankard Tree and Karthis al-Hezzar.

In-game description
"The long bow is similar to the short bow, except that the staff is about as high as the archer is, usually 6 to 6.5 feet. Even though the longbow is slightly slower then the short bow, it has more range and is more accurate. The smooth staff of this bow is warm to the touch, just a hint of the energy that surges through the wood."