Features: 1.Sudoku,Sudoku Game with key-chain 2.Sudoku game ,Square with size of 6*6 3.LCD size:3.6*3.1cm Features:1.Sudoku,Sudoku Game with key-chain 2.Sudoku game ,Square with size of 6*6 3.LCD size:3.6*3.1cm 4.Time display,Key tone 5.Battery: 1*CR2032 battery(included) Sudoku