I was looking for a reasonably sized armrest and reasonable cost. I opted for this model, I installed easily and correctly fills the space. I had to strengthen the basis for a screw of the stand was broken in the base. the arm is made of molded plastic, use I detect vibrations. so I add the stiffeners media that severely limit the vibration that the wheelchair is observed on degraded roads. advantages: a nice design, a relatively small footprint disadvantages too thin plastics, metal too thin, so that the whole is not very rigid and vibrates. provide reinforcements and stiffeners. conclusion armrest small enough in size, but nice that vibrates a bit.