They are slim and have a soft waterproof covering that slips easily under your arms and feels good on your bare skin.
Thomas Fetterman Poron Underarm Crutch Hand Grips 
Protect your hand & shoulders
The black vinyl wipes clean
Slip resistant
Have thick shock absorbing Absorbalite
The tornado crutch tips, are designed to act as shock absorbers, they have a thick shock absorbing absorbalite gel core. That absorb the shock the crutches put on your shoulders every time you step forward. They are also designed with a pivoting action that enables more of the bottom to keep constant contact on the ground surface to eliminate having the crutches slip preventing falls. The Poron hand grips for under arm crutches are made of “a tough PVC vinyl shell covering a shock absorbing polyurethane closed cell sponge center. The vinyl shell’s surface does not stretch so there is no skin sheer, resulting in reduced calluses and increased comfort.”
They will cost you around $70.00, if you will need crutches for several weeks or months it is well worth the money.
