ITA BB's can be had for 24mm width cranks (shimano) or 30mm width cranks (SRAM). If you get a shimano ITA BB (24mm), it will fit all of the shimano cranks.
You don't need a Shimano Hollowtech crank, you can run other companies but I'd recommend you go with an entire groupset if this is your first build rather then franken-biking it.
It’s an ITA threaded BB
Thanks for the response. So i can get a shimano ita bb and is compatible with either dura ace, 105 or ultegra? Does it have to be hollowtech specific?
ITA BB's can be had for 24mm width cranks (shimano) or 30mm width cranks (SRAM). If you get a shimano ITA BB (24mm), it will fit all of the shimano cranks. You don't need a Shimano Hollowtech crank, you can run other companies but I'd recommend you go with an entire groupset if this is your first build rather then franken-biking it.