These are a set of three rubber suction cup feet from manfrotto that also feature a retractable stainless steel spike the suction cup increases the footprint of the legs by almost 20 times giving much greater stability when needed the steel tip provides a firmer footing on soft ground the foot can be removed and replaced at will 440sck2 for tripods 440 724b 728b 190mf3 756mf3 and 055mf4