It isn't custom made parts, they are mass-produced reinforcements for your TM SR-10 or for your JG BAR-10.
The side panels were made from reinforced, alloyed aluminium. The pins were made from brezon which is really hard material. The other parts were made from ST-37 steel. You can adjust the trigger force - trigger lenght. The trigger move really smoothly. Basically we sold them with 5 years warranty.