This is a Midwest Industries Accessory known as the M-LOK Bipod Mount, model MI-MBP.
Midwest Industries is a proven leader in the firearm industry. Made in America" focusing on the small details to make your rifle platform better. The addition of their M-Lok Bipod Adapter will give you modularity and a solid Bipod lock up to your M-Lok handguard. Made to work with Harris type bipods.
Features:
Made to work with Harris type bipods
6061 hard-coat body with a steel stud