These are four cherubim which attend the throne. See commentary on Revelation 4:6. seven golden bowls
Bowls is φιάλας [phialas] : A bowl used in offerings.1 Considered the equivalent of a מִזְרָק [mizrāq] , the bowl used for sprinkling the altar (basins , Ex. Ex. 27:3; Ex. 38:3) or a bowl used for drinking wine (Amos Amos 6:6). Here, we are to understand a parallel between these golden bowls of wrath and the golden bowls of incense, which are the prayers of the saints (Rev. Rev. 5:8+). The wrath contained in these bowls represents Gods response to the mountains of prayers over the ages by the saints of God to avenge the blood of the martyrs (Rev. Rev. 6:10+) and to bring His kingdom to earth (Mtt. Mat. 6:10; Luke Luke 18:7-8). These seven most severe plagues are reminiscent of Gods promise to Israel if she refused to heed his prior judgments designed to turn her back to Him. And after all this, if you do not obey Me, but walk contrary to Me, then I also will walk contrary to you in fury; and I, even I, will chastise you seven times for your sins [emphasis added] (Lev. Lev. 26:27-28). See Seven: Perfection, Completeness. The seven bowls are poured forth in the next chapter (Rev. Rev. 16:2+, Rev. 16:3+, Rev. 16:4+, Rev. 16:8+, Rev. 16:10+, Rev. 16:12+, Rev. 16:17+). In the pouring forth of these bowls, God will administer His wine of wrath upon those who worship the Beast. See commentary on Revelation 14:10. of the wrath of God
These represent the culmination of Gods wrath poured out during the Tribulation. His wrath is associated with the entire Tribulation. See commentary on Revelation 6:17 and Revelation 15:1. who lives forever and ever
Τοῦ ζῶντος εἰς τούς αἰῶνας τῶν αἰώνων [Tou zōntos eis tous aiōnas tōn aiōnōn] , the living one into the ages of the ages. Jesus described Himself with an almost identical phrase, see commentary on Revelation 1:18.
1 Frederick William Danker and Walter Bauer, A Greek-English Lexicon of the New Testament and Other Early Christian Literature (Chicago, IL: University of Chicago Press, 2000), 858.