All feet are available on separate listings with different features. For:
Plain feet, without the pre-fitted M8 bolt, go to - https://www.ebay.co.uk/itm/311428968766
Larger diameter versions of these feet, go to - https://www.ebay.co.uk/itm/122551405889
Larger diameter versions of the plain feet, go to - https://www.ebay.co.uk/itm/121756254577
Larger feet with 25mm x 17mm spigots in place of the M8 bolt, go to - https://www.ebay.co.uk/itm/311896442934
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Ball Foot
Diameter - 66mm
Height - 100mm