Nest Thermostat E Series Programmable Home Wi-Fi Thermostat T4000ES WhiteNest brand products, The Thermostat E Series Programmable Home Wi Fi Thermostat. Model: T4000ES. White version. Works with most 24V systems, the connector can accept only one of the following: Y2, W2, or O B. Go to nest. com works for full compatibility. Requires phone or tablet with iOS 8 or later, or Android 4 or later. Features: Nest E is a learning programmable thermostat, which utilizes smart technology to suit your temperature preferences