http://www.sram.com/_media/pdf/service/PowerLock.pdf.
just checked mine and there both M.
what ja recon.

i recon go get yourself a free replacement.

Mine have been fine…….seems like a lot of hassle to return them when they are doinf alright. Chains break/life goes on.

So are "Power Locks" 10 sp chain only then? Seems to so I seem to have escaped.

SAFETY RECALL
SRAM PowerLock® Bike Chain Connector
erLocks® with date codes M or N can break and cause the chain to detach.

werLock® connectors were sold:
By themselves from January 2009 through August 2009.
With SRAM 10-speed bike chains (PC-1030, -1050, -1070, -1090, and -1090R)
from January 2009 through August 2009.
As original equipment on some Guru, Surly, Salsa, BMC, Serotta, Seven, &
Ridley brand bikes from April 2009 through August 2009.
If your bike has an affected SRAM PowerLock®, stop riding it immediately
and return the PowerLock® to a SRAM dealer for a free replacement.
For more information or for assistance, contact SRAM at
(800) 346-2928

Chains break, face goes crunch. I'd avoid using a product in my chain that has been recalled!