These are standard '130 size' DC hobby motors.

Features:

• Motor: 6V
• Speed: 10800 rpm
• Voltage 4.5V-7.5V
• Current: 0.18A
• Motor tail lengthening: shaft lengthening 8.2mm

Contents:

• Infrared speed sensor module (two-way speed measurement is possible)
• A-shaped precision metal fixing parts * 1
• 12 grille code wheel * 1
• High-quality 130 motor * 1 (tail lengthened by 8.2mm) 
• Terminal wire speed 150mm long * 1 group (one terminal has a terminal, one wire is cut and tin is added)