Differences between 2 Nordic components extension tube

[Desmoul from France]

Do you know what is the difference between the two extensions tube made by nordic components:

http://nordiccomp.com/retail/shop/nc-ex ... -for-12ga/
and
http://nordiccomp.com/retail/shop/nc-ex ... mbly-12ga/

I would like to buy the MXt extension, but it is out of stock at Brownells, can i use the other with the same performance ?

Thank you for yours answers.

[Vitaly]

As I can see, the only difference is that MXT Shotgun Magazine Extensions has a clamp groove to allow our clamp to fit more precisely on the tube.

[Synchronizor]

Besides the clamp notch, another difference is that the MXT extensions use the same thread on each end of the extension tube, allowing the tube to be installed in either orientation so that the user can place the off-center clamp notch in the place that works best for their particular build.

The EXT extensions without clamp notches use a smaller-diameter thread on the front end to allow for a more streamlined cap.

[Desmoul from France]

Thanks you Vitaly and Synchronizor for your answer.

It's difficult in France to have help for the 870. I make an order of the Nordic component extension(not the MXT because it's not in stock) at Brownells online store.

Olivier.