The p43 Snark loop is a period-43 oscillator made from Snark reflectors. It is the smallest of an infinite family of Snark-based adjustable glider loops that can have any period from 43 up.
There are much smaller glider loops containing four gliders, with a total signal path length of 216+8n and therefore adjustable to any period of the form 54+2n. However, this is the smallest loop that can contain eight gliders, which is a requirement for universal adjustability.
A 226-glider synthesis of this oscillator was discovered by Jeremy Tan on June 9, 2019.