Primary Airsoft MK23/SSX23/M4 Gen 4 Adapter
What more needs to be said?
If you are thinking of taking the plunge and going to HPA then you NEED one of these!
They are the best on the market of their sort.
These adapters include a Y&P mag which works wonders with the Toyko Marui, Novritsch SSX23 and other clones.
* Please note no images have been released by Primary yet, I will get some added soon