This carburetor is the replacement for many scooters of the 139QMB 50cc family. It fits the GY6 50cc 4-stroke models. 

Features:

• 2-wire male plug
• Electric choke carb
• Hard plastic top
• Rubber drain line
• Air filter mount ID: 34mm
• Intake ID: 18.5mm
• Can be used with a 38mm or 40mm ID air filter