No. Vivo Y81i does not come with the earphone in the box. You have to purchase it separately.
Vivo Y81i comes with 5V / 1A charger. It does not support the fast charging.
Vivo Y81i is made of Aluminum Alloy and industrial grade polycarbonate material.
You can record up to 1080p resolution videos on Vivo Y81i. You cannot record 4K videos via Vivo Y81i.
Yes, Vivo Y81i does support the face unlock.