The IMI Defense FSG1 –Front Support Grip is a light weight,highly durable fore grip that provides ergonomically optimized to reduce muscle fatigue, speed target acquisition, lower the recoil and increase rifle control. 
It is the only kind of a grip on the market that is designed to continuously merge with the AR15/M4 magazine well. 
Please scroll down to image number 6 for a better view. 

Features:
• Made of high quality fiber reinforced polymer compound.
• Highly durable one piece design.
• Fits any 1913 rail, no installation tools required.
• Designed to continuously merge with the AR15/M4 magazine well.
• Available in black/desert tan/O.D green