The major advantages of these pullers are :

The two / three jaws slide backward / forward on precision ground tee section. The jaws are coplanar over the entire width thus ensuring full Grip over the machine element requiring extraction.
There is a facility of locking puller jaws to avoid any slippage while extracting machine elements like bearings, pulleys, couplings etc.
All parts are made from high-grade alloy steel, toughened to 25-30Rc and precision ground to maintain parallelism of jaws. Spindle is of EN 24 and Nitrided. This ensures high Load Carrying Capacity and also gives long life to the puller.
There is a rotating center to reduce damage to shaft. A specially designed tommy is provided to apply extra torque required to remove jammed pulleys / couplings. A gunmetal ring has also been provided to eliminate damage to spindle.