Only pay for what you use. This LPK is perfect if you plan on upgrading your trigger to something a little nicer than a standard Mil-Spec fire control group. This lower parts kit does not contain a Fire Control Group or Trigger Guard. If you don't plan on upgrading these components please choose from one of our complete AR-15 LPK's. Please note: if you are purchasing this kit for our 0940 or 1045 receivers you will not use the supplied bolt catch spring or bolt catch roll pin. You need to use the lightened spring kit included with the receiver. Lower Parts Kit (LPK) includes: B5 Systems Type 23 P-Grip in Black Pistol grip screw Safety Selector Safety Selector Spring Detent Selector Bolt Catch Bolt Catch Spring (not for 9mm/40sw/45acp use) Bolt Catch Button Bolt Catch Roll Pin (not for 9mm/40sw/45acp use) Front Pivot Pin Rear Take Down Pin Take Down Detent (2) Take Down Detent Spring (2) Magazine Catch Spring Magazine Catch Button Magazine Catch Buffer Retainer Pin Buffer Retainer Spring "