Mayweather announced Tuesday that he plans to use eight-ounce gloves for the upcoming bout August 26th against McGregor. This is contradiction to was was reported when news of the fight broke.
Mayweather stated on his Facebook page
Don't believe what you hear in the media. Don't believe what you hear on blog sites. If it's not coming directly from me, then it's not true. I'm telling McGregor, "Let's fight in 8 oz gloves". McGregor can fight in any brand he prefers or chooses. I'll be wearing 8 oz Grant gloves. Whatever advantage McGregor needs to feel more comfortable in the ring, I'm willing to accommodate. Let's give the boxing and MMA fans what they want to see.
According to Dana White, during the negotiation process one of the sticking points on the deal was the difference between boxing and mixed martial arts equipment. UFC gloves are usually around four ounces with open fingers, and boxing gloves range from eight-to-ten ounces.
Now it appears they have compromised to use eight-ounce gloves however It remains to be seen whether this will make a difference.
Boxing
The main reason boxers wear gloves is to protect their hands and damage to their faces. Boxing Gloves are designed to pad the knuckles and support the fighters' wrists and thumbs so they do not break on impact. The heavier a glove, the more padding. Boxing glove thumbs are stitched to the glove so the fighters cannot move their thumbs.
MMA
The gloves worn in MMA are different. They are usually around 4 oz. and have finger holes so the fighters can grab each other. They also have movable thumbs.