APS 13mm Spring - 150 Newton (SRS & TAC-41) SP-STAL-224 This gives the Kythera trigger

This gives the Kythera trigger the distinct break and reset you would expect when firing a real single-action firearm

For Action Army AAP01 airsoft replica

You can use the camera handheld or mount it to a helmet (night vision goggles)

and is recommended for all gas blowback pistols and rifles

It includes a 14mm CCW thread

APS 13mm Spring - 150 Newton (SRS & TAC-41) SP-STAL-224 This gives the Kythera triggerAPS 13 mm, 150 Newton spring. This spring follows the APS 13 mm standard (for a 9 mm outer diameter spring guide). It fits any rifle compatible with this standard, including all SRS models (except the push mechanism) and all TAC 41 models. When compressed to a length of 99 mm, it delivers 150 Newtons (+ 5%, approximately 9 kg of force). This spring features a black electrophoresis coating and laser marking for quick identification.