Attaching a second pistol grip to the handguard of an AR to create a vertical foregrip is a practice going back to Vietnam.

In the early 2000s, Knight’s Armament Company iterated on the idea with purpose built foregrips made with built in mounting rings for Surefire 6P flashlights, and a wired button controls.

These “Gangster Grips” were used by CAG (Delta force) in the early 2000s.

The grips made by KAC used Lone Star grips as a base, making them distinctively more rounded than A2 grips.

Reproductions or field improvised versions of the grips often use the more easily sourced A2 grips.

Here is a photo from Iraq that appears to show an improvised gangster grip. Note that it is A2 and rather than a built in button, a switch is taped to the side of the grip.

These grips were never sold in any significant way by KAC to the public. Grips like the Surefire M900 did basically everything they did but less awkwardly.

As the U.S. military got more familiar with vertical grips, improved lights, and layouts for mounting them on rails, dedicated grips with lights became less popular. A light attached to the side or off the top of the handguard, with a pushbutton or a switch taped to a normal vertical grip became practical and widespread enough to make the “Gangster Grips” entirely obsolete.