Hiperfire trigger excellent but customer service less than satisfactory - HIPERFIRE HIPERTOUCH ECLipse AR Fire-Control Group, 2.5/3.5lb Pull Weight

It is an excellent trigger. I have two, and the first one went about 6000 rounds in my MPX before the hammer spring broke in two during a match. The problem is that Hiperfire's customer service is less than satisfactory. I couldn't find anything on their website about spare parts for the hammer group and no one replied to my email asking where to purchase a replacement hammer spring. I finally found one at JJ Supply. If you are shooting an MPX I recommend that you buy replacement hammer springs.