Material:Glass+PlasticColor:Blue，Green，Orange，Purple，YellowSize:16x8.2 cm/6.3x3.2 inchIdeal for teaching time management， ADHD， Autism， SEN， Visual Clue for Homework， Playing Games， Concentration Behaviour Management， Time Out and more...Our Full Range of timers includes:2 Minute - Orange/ Orange sand3 Minute - Yellow/ Yellow sand5 Minute - Blue/ Blue sand10 Minute - Green/ Green sand15 Minute - Purple/ Purple sandKindly Note: this product is not a toy， adult supervision required， item contains glass.The sand timers are accurate with on occasion a small margin of error， typically a few seconds over or under.