NK-27-21C NK-27-21C-1/2 NK-27-21C-1/2-V NK-27-21C-3/4-R NK-27-21C-5/8 NK-27-21C-7/8-R NK-27-22C NK-27-22C-1/2 NK-27-22C-1/2-V NK-27-22C-3/4-R