Cotterman GripTips are our own design, specially made for use on Cotterman products for optimal grip and durability. Replacement 4 pack kit for 1" diameter tubing on Cotterman rolling metal ladders (mobile ladder stands) specialty ladders and custom solutions. Crutch tips are a proprietary design and should be the only crutch tips used on Cotterman rolling metal ladders; they are Custom made for Cotterman using an optimal durometer for grip and rigidity and a 1" internal bonded washer for added durability.