Our family adopted Kia - she is amazing and very affectionate! You can only guess with mixes and your veterinarian can give you an opinion. These pups are definitely labs (possibly) crossed with a boxer - also called boxadors
As a side note, when we had our home visit an MLRR volunteer noted that they don't accept pit bull mixes, due to their possible aggressiveness. Sometimes it is hard to know with mixed breeds because they could have a multiple breed background (just like people.) Rest assured that any breed mixed with a lab is GREAT!