APS compatibility

[SuckMySock]

Hello,

I have been looking for upper M4 receiver that does not have forward assist, managed to find this:
http://www.aps-concept.com/index.php?route=product/product&product_id=1314

Does anyone have any info on its compatibility with M4 lower receivers and V2 gearboxes from other brands?

 

[AK47frizzle]

I can't view the link atm, but I know that JP reciever by madbull (I think) don't have forwars assists either. Comes as a set for normal v2s