Neodymium Magnet 18 mm x 15 mm OpenLog (Open Source Data Logger ) we can see the 5x5

we can see the 5x5 LED array that you can use as a light sensor

Input Offset Voltage : 7 mV

upgrade-ability and expansion

Even if the bottle cap is screwed tightly

Neodymium Magnet 18 mm x 15 mm OpenLog (Open Source Data Logger ) we can see the 5x5Neodymium Magnet (NdFeB ) is a rare earth magnet made from an alloy of Neodymium, Iron and Boron to form the Nd2Fe14B tetragonal crystalline structure. They have replaced other types of magnets in many applications in modern products that require strong permanent magnets and magnetic fasteners such as electric motors in cordless tools,hard discs drives. Features : Dimensions: 18 mmx 15mm. Direction of magnetisation: Axial. Max. temperature : 80 C.