B5 Systems M4 Multi-Tasker Tool, Multi-Tool, Black MTR-1395 The MultiTasker M:4 AR-15 Tool is a 1-piece multi-tool for the M4 carbine designed and manufactured in conjunction with B5 Systems. The M4 is precision machined from solid barstock using wire-EDM/CNC" and fits discreetly with no visible footprint inside a specially inletted buttpad made by B5. Easily accessible without tools simply by pressing the release tabs on the buttpad. Dot coded to indicate functions.