The 
NUPROL QD Sling Mount Keymod
 in Tan is a specific airsoft accessory designed to provide a quick detachment (QD) sling point for Keymod rail systems. 
 
 
Product Details and Features
Compatibility: Designed for use with Keymod rail systems. It is not compatible with M-LOK or Picatinny systems unless specified with an adapter.
Color and Material: The mount base is available in a Tan finish, typically constructed from a durable metal alloy (likely aluminum). The corresponding QD sling swivel is generally made of steel for strength.
Functionality: It provides a secure attachment point that allows for the quick attachment and detachment of a sling via a push-button mechanism.
Design: Features an anti-rotation design to prevent the sling swivel from unwanted spinning.