Nearly everything you'd need to update the MB01/APS96 replicas. Parts are totally new and unused.
PDI Raven cylinder kit
PDI trigger sear
Airsoft Pro reinforced and enhanced trigger
If you have any doubt, here is a list of compatible replicas, there might be others so don't hesitate to ask me :
Maruzen APS96
Cyma CM.706
ASG AW308
Well MB01
Well MB01AE
Well MB05
Well MB05AE
Well MB08
Well MB08AE