Kelp Blue Lady fins are specifically designed for small feet (37-39). The footpocket is made in thermo-rubber with two different hardnesses. The blue areas are softer to make them more comfortable even without using the neoprene socks. The black parts, on the other hand, are rigid in order to transmit to the blades all the energy of the finning. There is an anti-slip pattern on the heel. Thin channels leave the blade free to display a wide, regular, and uniform arc. The Kelp blade, blue in this version, is made of low-density polypropylene, a special high-tech polymer. It flexes with small effort evenly and it has an excellent elastic return. The blade is characterized by its semi-transparency and the keyhole at its top that decreases drag during the kick cycle. The hole, in fact, relieves water from the part of the blade that works less, thus it acts as a channel for water. At the end of the blade, there are two rubber guides at the top and bottom with the purpose of channeling the water and canceling the horizontal drift of the fin while finning.