A21 (End of road stretch with roadwork) is a Swedish road sign, belonging to the category of warning signs (group A). Closer provisions are given in the road sign ordinance (SFS 2007:90): The sign indicates the endpoint of a stretch of road with roadwork which has been marked with sign A20 (Warning—Roadwork). The sign shall not be put up if it still would be apparent where said stretch of road ends.
According to the regulations regarding the sizes of road signs and other devices (VVFS 2008:272), the sign's long side shall be 0.60 metres, while the short side shall be 0.40 metres.
transportstyrelsen.se 



Source materials for this file are available from Commons Archive:

Sweden road sign A21-1.eps
Government of Sweden