JMK Vertical Foregrips are perfect for applications with limited rail space. The two-piece design allows both Picatinny or M-LOK mounting patterns and can be purchased in a standard or +10 mount. All grips are machined from black walnut.Features: Solid black walnut Heavy-duty 5/16" main stud Picatinny version only uses 2 slots and 1-1/8" of rail space M-LOK version only requires a single M-LOK slot and 1-5/16" of rail space. Made in USA