Founded by engineer George M. Pfundt in 1936, GMP started George M. Pfundt operations in a downtown Philadelphia building as a specialty machine shop doing work for the local Bell Telephone Company and Philadelphia Electric Company. GMP expanded its family-owned business to a production shop after landing a contract with Western Electric Company and, subsequently, forming a close relationship with Bell Telephone Laboratories in Murray Hill, N.J.  These relationships enabled GMP to manufacture prototypes of products for experimental use within the Bell System.

In 1949, GMP and Bell Telephone Laboratories joined forces to pioneer the first modern automatic lashing machine, the Model B Lasher, establishing the telephone industry’s standard in lashing technology. Cable lashing machines sometimes called “lashers” or “spinners”, are designed to wind stainless steel wire around telephone, power, and multi-media cable, thereby securing or “lashing” the cable to the supporting messenger strand between poles. Since its introduction, the company has produced over 45,000 lashing machines, some manufactured in the 1950s are still on the job today.

After 20 years in Philadelphia, it was clear the company had outgrown its original factory building.  George acquired some land and contracted to build a new 100,000 square foot headquarters and manufacturing facility.  In 1957 the company moved into a its new facility in Trevose, PA (a Philadelphia suburb), offering sufficient space for business expansion.

In 2004, GMP acquired UK-based manufacturing company CBS Products LLC, adding cable blowing equipment such as the Breeze, the Tornado, and the AccelAir to their large assortment of equipment. The company would later add more cable blowing equipment to its line in order to meet industry's need and service varying cable type sand sizes. Models include the Airstream, Whisper, and AccelAir2.

GMP was acquired by family-owned and operated Klein Tools, Inc. in 2017.  Today GMP is still recognized as a premier worldwide supplier of specialty tools and equipment for the outside plant marketplace. The company’s products are known for their robust design and durability to withstand many years of frequent use.