The drawings are based on the well-preserved remains of an in-situ fulling stock, with the system of gears and the water wheel that drove it, from the former Factory-isaf woollen mill that housed them. It was fed by the fast flowing Afon Cegir. The equipment is the sole known example of its type in situ in Wales, thereby representing a unique survival of a former widespread and ubiquitous industry and one of only two known in the UK.

The fulling stock, wheel and gears occupy the remains of the north-eastern end of the mill. The 6.1m diameter back-shot water wheel wheel has the words ‘Samuel Owens Maker No. 87. Newtown Foundry 1859’ and had 40 wooden buckets and an iron axle. The wheel is attached to a pair of large primary gears, a shaft running from these, through the factory wall to drive the upper gear system. These three large gears are mounted on a wooden frame on what was the main factory floor level, the largest and lowermost of these being set within a stone lined pit. The upper gears on the frame are connected by an overhead belt to the pair of lower gears driving the fulling stock located in the former cellar. A smaller gear and wheel above the upper gears drove machinery in the factory to the south-west. The lower gears and cast iron tappet wheel of the stock remain in situ within stone lined pits in the cellar floor. The striker plates of the tappet wheel drove a pair of wooden mallets, or stocks, into the oak-lined iron tub or box containing the cloth. Two tapering wooden poles used for locking the mallets, are rare survivors and the upright ornate cast-iron plate in which the poles fitted is located beyond the tappet wheel. The outer faces or cheeks of the tub are covered by cast-iron plates with the words ‘R Kilburn, Millwright of Holbeck Leeds’ and are joined to a vertical, circular cast-iron column or stock-back supporting the axle and shank of the mallet mechanism.