Golden Gutter of Kaaba
The Kaaba is in Mecca. For Muslims, it is the most holy place.
Rain can fall on the roof of the Kaaba. So a gutter was made to collect the rainwater and carry it away.
This gutter was renewed in the time of Sultan Suleiman the Lawgiver. A sultan was an Ottoman ruler.
Later, old gutters from the Kaaba were brought to Topkapı Palace. This happened in the time of Sultan Murad the Fourth. It also happened in the time of Sultan Abdulmecid.
So this simple object is linked to Mecca, to rain, and to the care that Ottoman sultans gave to the holy places.