28P7.3 is an unnamed period 7 oscillator discovered by "Bullet51" on December 26, 2017. In terms of its 28 cells, it is tied with oscillators burloaferimeter, 28P7.1 and 28P7.2 as the smallest known period 7 oscillator. It contains an eater 1 that can be replaced with another copy of this mechanism. Its boat can act as an eater 1, and thus this oscillator is infinitely extensible. Because its boat acts as an eater 1, it can eat gliders, LWSS, MWSS and loafers (with the help of an eater 1).