Here's a review of the ZCI v2 complete M4 gearbox. I got it from http://www.ak2m4.co.uk, it is currently available for £55.
The gearbox comes packaged in a nice, form-fitting blue foam box. Very nice quality packaging. It's a v2 gearbox with a few special features- QD spring guide, microswitch trigger, special selector plate. I'll explain more later in the review.
