The item is a pair of floating glass balls previously used for fishing which are olds item for about 50 years ago.
How to make glass fishing floats (and ideas for displaying them
Large Vintage Glass Japanese Fishing Float w/ Rope Net 14
FISHING NETS FLOATS
Japanese Glass Fishing Floats, 4 Softball Size, Authentic Glass
This is a glass float. Depends on custom in your country also.
Vintage Japanese Fishing Float Glass Ball Buoy Net Roped
BUOY
BUOY
Vintage Japanese Fishing Float Glass Ball Buoy Net Roped
Japanese Glass Fishing Float Ukidama Buoy Ball Vtg Bindama Rope
Japanese Glass Float DIY Succulent Display - Tie One On! - Birdz