These are leftover glass mosaic tiles used for a handmade project. Each individual tile is 15mm in both length and width. Some are on sheets, and some are loose. Everything in the first photo is included. The glass makes them quite heavy. For reference, the fourth photo shows an area where they were used randomly. I believe they are products from Nagoya Mosaic, but there is no marking, so I'm not certain. Please understand that these have been stored at home for a long time. Due to being glass, there may be some chips or imperfections.