STMicroelectronics X-NUCLEO-53L4A3 Expansion Board is a Time-of-Flight (ToF) high-accuracy proximity sensor expansion board based on the VL53L4ED for STM32 Nucleo. This expansion board assists learning, evaluating, and developing applications using the VL53L4ED ToF high-accuracy proximity sensor with extended temperature capability. The X-NUCLEO-53L4A3 board includes a cover glass holder to accommodate three spacers of 0.25mm, 0.5mm, and 1mm below the cover glass to simulate various air gaps. A small oval cover glass fitting the sensor is also included. This expansion board is equipped with Arduino® UNO R3 connectors. The X-NUCLEO-53L4A3 expansion board operates within the -40°C to 105°C effective sensor temperature range. The X-NUCLEO-53L4A3 board is RoHS, CE, UKCA, and China RoHS-compliant.