This sale is for a used but still really excellent condition Bronica ETRS Grid focusing screen – suitable for the four Bronica ETR series cameras (ETR, ETRC, ETRS and ETRSi).
This screen is in great condition – boxed, with just two faint marks on the screen near one corner but otherwise really clean. Far far better than most.
Try finding another one! The only other one I can see (at the time of listing) is in Japan at more than double this price – plus shipping and tax!