Working voltage: 5V; One round number of pulse: 20 The Material of Knob Cap: aluminium alloy；The Specification of Knob Cap: diameter: 15mm/ 0.59in; height: 16.5mm/ 0.65in The rotary encoder can count the number of pulse output during rotation in the positive direction and reverse direction through the rotation and this rotation counts are not limited With the key on the rotary encoder, you can reset to the initial state, that is, counting from 0 Package content: 5pcs x Rotary Encoder Module + 5pcs black Knob . The rotary encoder can count the number of pulse output during rotation in the positive direction and reverse direction through the rotation and this rotation counts are not limited. With the key on the rotary encoder, you can reset to the initial state, that is, counting from 0. The Material of Knob Cap: aluminium alloy