The "sign" (Revelation 15:1) has now vanished from John's sight and he looks once more at the heavenly temple which is opened again (or, perhaps, still--note Revelation 11:19). The same angels he had seen in the sign now emerge from the temple, dressed as priests with golden girdles (Leviticus 16:4) and ready to administer the seven last plagues on the earth.

Source:

KJV Defenders Study Bible, by Dr. Henry Morris, Ph.D.
Publisher: Thomas Nelson
Language: English
DEF 10 ISBN 0-529-10444-x
DEF 10-1 ISBN 0-529-10445-8