Univolt General Purpose Printed Circuit Zero Board - 4x4 Inches LM339 Quad Voltage Comparator 14-Pin SMD VRx and VRy pins are

VRx and VRy pins are used to retrieve analog signal which contains position coordinates of X-axis and Y-axis respectively

4 Cell AA Battery holder box is a simple holder for four AA cells in series

This is a - SMD Resistor with a resistance of 0 ohm (0E)

For this reason

Univolt General Purpose Printed Circuit Zero Board - 4x4 Inches LM339 Quad Voltage Comparator 14-Pin SMD VRx and VRy pins areIt's a 4x4 Inches Uni volt General Purpose Printed Circuit Zero Board. This is commonly known as Perf Board, Practice Board, General Purpose PCB, Zero Board. This Is A High Quality Single Sided Fr2 Phenolic General Purpose PCB. It Is Used For Rapid Prototyping Design Features Size 10x10 cm (4x4 Inches) Brand Univolt This Is A High Quality Single Sided Fr2 Phenolic General Purpose PCB It Is Used For Rapid Prototyping Design Copper Layer Is Laminated