 Both lenses have image stabilization (IS).The EF 24–105mm f/4L IS USM and IS II USM version use a ring type ultrasonic motor, whereas the new EF 24-105mm f/3.5-5.6 IS STM uses Canon's STM stepper motor, which is quieter during video usage.The new EF 24-105mm f/3.5-5.6 IS STM weighs slightly less (525 g / 18.52 oz versus 670 g / 23.6 oz) and costs roughly half the price of the EF 24–105mm f/4L IS USM.