Rainier Industries new EVO for grip:

Very cool. Take a look.

According to Guns and Tactics here's what It'll do

"Channel and manage your cables
Take a beating, even if you’re slamming it against barricades
Let you maintain your grip even when your hand is sweaty, muddy, bloody, greasy, or slimy (but not wimpy or sissy).
Adjusts from vertical to canted for preferred hold
Help you more efficiently manipulate the weapon
Gain +1 Bonus Action around barricades or doing transitions...."

See it here at Rainier Arms: https://www.rainierarms.com/rainier-...1973_e3bbec019