This extended (3.75 ) blue-steel magazine is for the Hi-Point carbine. It comes with a follower, bumper/base plate and comfortable grip-sleeve made of an impact-resistant black polymer material; and uses heat treated Chrome-silicon wire for reliable feeding and long spring life.ProMag magazines are designed utilizing traditional stamping and welding of heat-treated high carbon steel. Every ProMag magazine is backed by a lifetime guarantee against manufacturer's defects. Features: Magazine body constructed of heat treated carbon steel with black oxide finish Injection molded magazine follower Magazine spring formed from heat treated chrome silicone wire Includes injection molded grip sleeve Made in USA