17-4 stainless steel, certified, aircraft grade, condition A, center-less ground to ensure absolute straightness, rust resistence, and consistency. Manufactured in a state of the art machine shop with CNC mills, lathes, drilling centers, and straightening machines. In house, digitally controlled, heat treating oven. All machines and materials are made in the USA. All machining is done on site, under strict quality control methods, to ensure the finest spear shafts available. 
 
Custom shark fin tab height and spacing configuration make these shafts ideal for use with inverted roller spearguns using a bridged muzzle. 3/32" shooting line hole drilled through the rearmost tab, at the tang transition, for maximum band stretch. 5cm tang length with euro notch. Standard 5/32"-24  thread pitch has been necked down for attachment of most 8mm/5/32" milled slip tip bases on the market. To get an ideal 7 1/4" shaft overhang with a  mounted slip tip, select a shaft length that gives you a 4-5cm overhang. Always consider the trigger take up, actual barrel length, and muzzle length, when calculating the overall length. 
For example: if you're using an Ermes Avatar handle with a reverse roller trigger mechanism (12cm trigger take up), a 110cm carbon fiber barrel, and a Manny Sub inverted roller muzzle (9cm), you will have an overall length of 12+110+9=131cm. If you select the 135cm shaft length you will have a 4cm overhang. That will leave just enough room for the slide ring to sit a 1/2" forward of the muzzle once the slip tip has been installed. Perfect!
 
The 8.5mm shaft diameter is best suited for taking down XL pelagic species such as tuna and marlin
An 8mm shaft diameter is suffient for all other blue water species
 
110cm IR-135cm shaft length
115cm IR-140cm shaft length
120cm IR-145cm shaft length