TyeTec NMP blocks (NMP= "no moving parts") are designed for use in between the loop thimbles and loop block. The fixed part is spliced through the central opening or suspended, and the block is secured through the milled slots with stitching or with a simple cable tie to prevent twisting.
Our NMP-S block (S=Sail): for use with the mainsail reef. The NMP-S block also has an additional slot for attachment flat on the sail. Dyneema webbing is used to attach it to the sail.
A little hand stitching through the outer slots will prevent the block from turning. The webbing
should not be sewn closer than 2xB to the block
to lower compression force .
The NMP-D block (D=deck) for mounting on deck, on the mast, on a track or slide.
The NMP-D block is fixed through the central hole with a stainless steel screw. Two smaller screws on the outer radius hold the rope in position against the sheave. Without these two scews, the block can be used as a deflector, just flipping the line behind it.
The MWL specified relates to the horizontal force on the block with its lower face on the deck. The MWL can be lower for different types of attachment and in relation to the stiffness of the deck.