They’re cheap, they work (apparently), and they’re for your PTW.

The cheap plastic magazine revolution has finally spread to the PTW.  Which is great, because instead of $64USD for one mag, now you can buy 5 plastic ones.

Here’s the product page link from UNCompany.com:

http://www.uncompany.com/pageproductdetails.asp?prodid=23439

Product Description:

• Material: Plastic 
• Capacity: 120 Rounds 
• 5 Pieces in Package 
• For Systema M16 / M4 PTW Series only

And here the pic from that page, to make this post look longer than it really is:

SHAZAM!