Which of the following is NOT a common feature in scooters regarding brakes?

Scooters typically feature two hand brakes, one for the front and one for the rear wheel, which are operated using the right and left hands. Therefore, having both a right hand brake and a left hand brake is a common design in scooters. Additionally, many scooters do incorporate foot brakes to give the rider more control over braking, especially in various riding conditions.

The manual hand brake, however, is not a common feature in most scooters. Unlike bikes or other vehicles that may have an additional manual brake system, scooters primarily utilize the hand brakes and foot brakes for their braking system. This distinction makes manual hand brakes an uncommon feature in scooters, leading to the conclusion that they do not typically include this type of braking system.