SLAB: CNC Machined 6061 billet aluminum with a beautiful BLACK hard coat Anodized finish.  
The Commander size SLAB is 3/4" shorter than the GI size, just like the pistols they hold.

MAG: High strength polymer mag designed after standard issue, flush fitting 1911 magazines for 5" and Commander size pistols. This MAG allows the pistol to sit as low as possible on the SLAB and still provides sufficient clearance for a Lanyard Loop Mainspring Housing like those used on USGI pistols.