Here's what Fender say about the Mustang LT40S:

The Mustang LT40S is the newest addition to the popular Mustang LT series guitar amplifiers. It’s ideal for practicing and jamming at home, with 40 watts of stereo power, a pair of high-fidelity, full range 4-inch speakers, a super-simple user interface and full-color display. Mustang LT40S features a collection of presets covering a wide range of music—a “greatest hits” of electric guitar tones. The versatile signal chain with high-quality onboard amp and effects models produces amazing tones. And with the free Fender TONE LT Desktop app download, use your Mac or PC to edit, store and manage your presets with ease. The Mustang LT40S is a fun, flexible and easy-to-use modeling amp for any guitarist. It’s the only desktop amp in its class with such a rich feature set.