TPO (Thermoplastic Olefin) is sometimes referred to as TEO (thermoelastic olefin). TPO is a mixture of Polypropylene and a tiny amount of thermoplastic rubber, which gives the plastic better paint adhesion and flexibility. Olefin plastics are those waxy feeling plastics that tend to smear when sanded at high speed. They also tend to get "hairy" when you grind it, or saw it. It is used more and more often in automotive applications. Most plastic bumper covers are made from TPO. This package contains 30 welding rods. Each rod is 1 foot (30 cm) long and 5/8th inch (16 mm) wide and 1/16th inch (1.6 mm) thick.