It will be a 777-200. That is the only type of 777 United has. There are different seating configurations depending on which revision of the airplane is being used on the route. While it's possible to see which one is scheduled, it's not possible to be certain since aircraft swaps do occur. If you are in need of knowing which seat map your specific flight has, send me a Private Message with the date, time, class of service (F, C or Y) and flight number(s) and I will send you the seat map information.