44 Magnum, Hairpin Safety, 6mm Mount Threads, 303 Stainless Steel. This is one of the preferred gator units. about the same volume as the .38/.357 Mag. Can be mounted on a speargun shaft or any of our Rod &Ball Assys. Most hunters mount this unit on a wood dowel (pole) 1-1/4" x 6' long. Using our pole mount AS015 "Sold Separately". Rod & Ball Assembly Sold Separately. POWERHEAD WEIGHT: 4.6 oz.