Prices are in Canadian Dollars. In the case of a discrepancy between the store and online, the store info will prevail.
This base has a 1" diameter rubber ball designed to sit at right angles to the mounting rail. The u-blots accomodate rails from .5" to 1.25" in diameter. Black caps are included to cover the exposed ends of the u-bolt and a composite adapter can narrow the minimum diameter of the rail to .5".