In flight entertainment

Hi, many apologies if already asked but unable to find answers!
We are flying Gatwick to Barbados on February 10th, Premium Economy. Curiously it is on a Heathrow plane (all to do with number of upper class seats I think). Could anybody help with the following questions please:-
1. which In flight entertainment system/model will it be?
2. Am I right in thinking that as long as I have a USB plug from a phone or Ipad I will be able to connect into the system for playing items and limited amount of charging, or do I need a different type of socket on the end?
3. If I want to use my own headphones what sort of socket would I need on the end of these?
4. How good are the headphones supplied?
Many thanks
We are flying Gatwick to Barbados on February 10th, Premium Economy. Curiously it is on a Heathrow plane (all to do with number of upper class seats I think). Could anybody help with the following questions please:-
1. which In flight entertainment system/model will it be?
2. Am I right in thinking that as long as I have a USB plug from a phone or Ipad I will be able to connect into the system for playing items and limited amount of charging, or do I need a different type of socket on the end?
3. If I want to use my own headphones what sort of socket would I need on the end of these?
4. How good are the headphones supplied?
Many thanks