This Gripper Is the same as the 400 lb pull gripper, but has two 250 lb pull Neodymium magnets in place of the 200 pounders, giving it 500 lbs of total pull to ferrous materials.  The Stabilizer can also be requested for this model but must be by email or phone, due to it being a none stocked item. with teh Stabilizer it will give you a total of 750 lbs. of pull. CAUTION, this is a very strong unit!! This is a must have for the technician or individual that has to endure the elements while working in the field.The Gripper is a magnetic holder designed to hold a beach style umbrella in place on ferrous materials ( 6' to 7' umbrellas work best and pole size 1" to 1,1/4" ). Its main design is for the hvac field. It will attach to the top or sides of the unit. It also has a tightening knob to secure the umbrella pol in place.