The low-profile of this muzzle makes for extremely low drag through the water and the very clear sight pattern along the spear is usually reserved for open-muzzle designs. The muzzle accommodates two rubbers that are clipped into place preventing 'muzzle flip' when fired.  The shape of the muzzle guides the rubber in a straight line, parallel with the barrel and spear. 
 
The muzzle is constructed of bomb-proof glass reinforced polyamide and the critical muzzle-barrel interface consists of an extra-long internal spigot with external shrouds. 
 
The muzzle hole attachment point has been shaped to accept an optional stainless steel shackle recommended when a reel has been fitted. 
 
Will fit any Rob Allen barrel made since 2005.