Co2 tube from lightobject

I find a difference in the aluminum laser head between the supposedly
same tubes

The product is supposed to have manufactured by "Bill Laser Products",
with the model number being 1000.
Only one tube has an extension of the aluminum head(as shown in the
picture), while the other(s) does not have this(could post a pic. if needed

Not sure if this could affect the tube life in future(esp. the short aluminum laser head,
the one without the neck/grooved portion). The extra grooved portion adds about 5mm
to the total legth of the tube. The tube is supposed to handle upto 50W at 100% power.
Would sincerely appreciate if anyone from tech support/other members could shed
some light

keeping a close eye on the tube operating temperature/current etc.). I am also
not sure, if I need to contact lightobject for exchange due to the same reasons.
I would also note that the serial number on the long neck aluminum head
tube is later than the other(s).
Thanks/Best Regards
Raman Narayan