ALPS Superior Suspension Sleeve has superior comfort provided by ALPS Gel. The SFB features a NEW black knitted fabric that still allows the user excellent freedom of knee flexion. The SFB also achieves secure suspension by sealing with the skin without restricting circulation, while the Gel sticks to the amputee’s skin without causing shear forces. With a thinner profile, the SFB is an ideal choice for those concerned about bulk.