Review on RV Designer H715: Plastic Window Knob with 2-1/4 inch Diameter - White Interior Hardware by Dick Grayson

This product describes the shaft length exactly. He does not look at the diameter of the shaft, apparently the sizes are different. These knobs were the nice beige color I was looking for and if you get the right diameter they should be very easy to install with a Phillips head screwdriver. However, it was not possible to install it on my caravan from 1976 because the shaft is too narrow. And unfortunately, the shaft diameter is not specified in the product description, hence the low cost estimate. My recommendation if you want this - buy 1 and make sure it fits. If so, go ahead and get the rest you need. Or measure the diameter of the crankshaft and find a knob that matches that size.