A really nice and quality product!
I got the Unitine Fork with 5" x 1.5" caster wheels on a Quickie XTR wheelchair, for 5 years now. It have change my life since i got them. No more falls forward with straight stop on little stone. Less scratches on the bottom of furniture, doors, wall, ... It's easier to turn in tight space. The only negative point is that the axle's wheel is fragile and you have to block the screw with strong "lock it" to keep it from bending.