This is a Senshukai travel calculator. It is new and unused. I turned it on to check the operation, but please consider the battery as for testing purposes. The size is approximately 80 x 80 x 12 mm for the main unit, and the ring is about Φ20 mm. I haven't tried everything, but it has many functions. Please check the instruction manual. It is new and unused, but it is an old item. I have set the time.