According to the notes on the RCAHMS site, this standing stone is about 1.2m high, 0.9m broad and up to 40cm thick.
It is shaped like a wedge, with the edge to the east, and is famous in Balquhidder as the place where trials of strength took place. A large round water-worn boulder, named after the district, "Puderag," and weighing between two and three hundredweight, was the testing stone, which had to be lifted and placed on the top of the standing stone. There used to be a step about 18 inches from the top, on the east side of the stone, on which the lifting stone rested in its progress to the top. This step or ledge was broken off about thirty years ago, as told to me by the person who actually did it, and the breadth of the stone was thereby reduced about 8 inches. This particular mode of developing and testing the strength of the young men of the district has now fallen into disuse, and the lifting-stone game is a thing of the past. A former minister of the parish pronounced it a dangerous
pastime. Many persons were permanently injured by their efforts to raise the stone, and it is said that he caused it to be thrown into the river, but others said it was built into the manse dyke, where it still remains. There were similar stones at Monachyle, at Strathyre, and at Callander, and no doubt in every district round about, but the man who could lift " Puderag " was a strong man and a champion.
J M Gow's 1887 'Notes in Balquhidder: Saint Angus, curing wells, cup-marked stones, etc',
Proc Soc Antiq Scot, 21, 1886-7, 84.