The monosulfoxide of cyclo-heptasulfur was reported along with cycloheptasulfur itself in 1977,[cite]10.1002/anie.197707161[/cite] along with the remarks that “The δ modification of S7 contains bonds of widely differing length: this has never been observed before in an unsubstituted molecule. and “the same effect having also been observed in other sulfur rings (S8O, S7I1+ and S7O).” Here I take a look at the last of these other molecules, the monosulfoxide of S7, as a follow up to the commentary on S7 itself.[cite]10.59350/rzepa.28407[/cite]