GSh-6LP is a further, and probably most common these days, modification of the venerable GSh-6 series of helmets. Judging by the information provided in GSh-6A and GSh-6LP manuals, there is only one thing that got changed. It was a switch from a 6-pin to a 8-pin connection between the neckring and the helmet. Seems like it was done to allow for a more quicker and easier connection of the helmet to the neckring.

In addition to the change outlined above, GSh-6LP sets now started to contain two types of different neckrings - each fitted with a different rubber skirt. The common one, pinkish, skirt was for everyday flying. The second one, made out of gray rubber, was to be worn by pilots when they expected to operate in possible NBC conditions. Gray rubber skirt was made out of much stronger rubber and provided a better seal, thus allowing to use GSh-6 helmet as a respirator ( obviously only when helmet is connected to aircraft's oxygen system that could filter and clean air).

 

This and several following images depict GSh-6LP helmet. Note that it is very similar to the earlier GSh-6A.
 
 
GSh-6LP helmets are equipped with the same exhale valve as GSh-6A helmets - K-66N.
 
ID tag of the GSh-6LP size 3M helmet.
Neckring with an NBC rubber skirt. Also note that neckring itself has 8 openings, instead of 6 as it used to be in GSh-6A helmets.