O RING ONLY!!!!!!!The french style stainless steel straw guns are designed to be used with the sheath with green insert (slit) and 1/2cc wick and powder straw, or the 1/4cc. The spiral style stainless steel straw guns are designed to be used with the sheath with blue insert (unslit) and the 1/2cc wick and powder straw. ( A standard 18" AI gun is sometimes refered to as a 'french style').
Artifical insemenation straw guns are constructed of stainless steel in a variety of configurations. The basic gun design consists of a stainless steel barrel with flange at the top for the plunger fingergrip plus a stainless steel inner rod, or plunger, with a flanged at the top for plunging with the operator's thumb.
Most popular designs are O-ring or Spiral style. The style refers to how the insemenation sheath is affixed to the gun. In the O-ring style gun, the extreme top outer section of the barrel flares out. A slit sheath is used with this gun. The slit allowse the sheath to extend over this flared area and a plastic O-ring is then wedged up against the flared area holding the sheath in place. The spiral style gun has a spiral thread at the top outer section. An unslit sheath is used with this gun. The unslit sheath is twisted up onto this spiral threaded area, holding it in place.