These Proximity Sensors use high-frequency oscillation. There are available in a wide range of sizes to enable selection to match the installation location.
There are 3 products of Rectangular.
Super-compact Proximity Sensor
E2S
Advanced Performance and Wide Range of Selections in a Supercompact Size
Flat Inductive Proximity Sensor
TL-W
Standard Flat Sensors in Many Different Variations
Rectangular Standard Proximity Sensor
TL-N / -Q
A Wealth of Models for All Types of Applications