NUPROL Hand Signal Sights (RIS) in Black are novelty back-up iron sights designed for airsoft replicas to add humor and personality to a player's setup. 
 
Product Overview
Design: These sights replace traditional posts and apertures with sculpted hand shapes.
Gestures: The set includes multiple gestures, such as "flipping the bird" (middle finger) and "giving the V's".
Compatibility: Designed to fit standard 20 mm RIS / Picatinny rails.
Functionality: While primarily for novelty, they are functional as simple back-up reference sights.