/> 
Glock Beavertail / Backstrap Set, Battlefield Green (G20, G21 - Gen4 Only). This factory OEM Glock part is made to the same high standards as the parts already found in your Glock firearm. This part will help keep your Glock pistol in top shooting condition, or to keep as a spare for when you may need it.
The GLOCK Modular Back Strap (MBS) System enables the pistol to adapt to an individual shooter's hand size. Installing and removing the back straps is a simple procedure and adding or removing a back strap does not change the grip angle of the pistol.
The smallest back strap is integrated in the GLOCK MBS frame reducing the trigger distance of the standard size frame by approximately .08 in. The medium back strap adds approximately .08 in - equaling the size of a standard frame - and the large back strap increases trigger distance by a total of approximately .16 in.
