Ghost Inc. has combined their polished 3.5 LB. Drop-in Connector Trigger with a Wolff 4.0 LB. firing pin spring, a Wolff 6.0 LB. trigger spring and a Wolff reduced power firing pin safety spring in a kit. These combinations will give you the lightest smoothest drop-in trigger assembly you can buy! And you save some money! Not for self defense if you use the Wolff 4.0 lb Firing Pin Spring. If you want to use for self Defense or in a 10mm/45 caliber Glock use the Wolff 6.0 lb firing pin spring.