Brooke Foss Westcot was an English bishop, biblical scholar and theologian, serving as Bishop of Durham from 1890 until his death. He is perhaps most known for co-editing The New Testament in the Original Greek in 1881. He was an enthusiastic British imperialist.
This is the bible published by the Watchtower Bible and Tract Society which is the Jehovah's Witnesses. The JWs reject the deity of Jesus, the Trinity and the bodily resurrection of Jesus. Many Greek scholars have taken issue with this translation as they have changed verses to fit their beliefs. Because of criticism from biblical scholars, the translation has changed several times over the years. The Watchtower has never disclosed the names of whoever did the translation of this version for the sake of preserving humility. Consider the numerous gross errors, I can only conclude that there were no actual translators, they just published the original Greek and changed the English to suite their needs - that is my opinion, but I think the best explanation.
The two most common cited errors are John 1:1 and John 8:58. Though this translation is corrupt, it is still possible to use it to share the gospel with the JWs when they come to your door. For example, in John 8:58 they changed Jesus quoting Exodus 3:14 identifying Himself as the I AM who spoke to Moses. They changed I AM to "I have been". The problem is that if you read the context, Jesus was still accused of blasphemy. The Jews were not in the habit of stoning people for saying "I have been". They really needed to rewrite verse 59 as well to make it fit with their doctrine. Another example is found in John 2:19-21. They forgot to change this verse which clearly states Jesus telling of His coming resurrection. The Greek word "soma" is correctly used in this translation which means physical body. Speaking of the physical resurrection, they also forgot to change Luke 24:39, at least as of this time last year, the last time I had a visit from the JWs. Jesus clearly states that He has flesh and bone after the resurrection. Numerous other examples can be found in places such as Colossians 1, Philippians 2, and Hebrews 1.
There are several good resources written that can teach you how to share the gospel with a JW using their own bible. I have some of them on my Apologetic - Cult shelf on Goodreads. One thing to admire about the JWs is their zeal for the Word of God, so if you can train yourself to have the discussion, this bible can be a great tool. I would NOT recommend having this bible unless you are thoroughly grounded in essential Christian doctrines and know scripture well.