The vessels were similar to the Soviet Project 205U Tsunami-class missile boats, given the NATO reporting name Osa II.

Tuisku and Tyrsky were also modernized into fast minelayers, but less extensively, removing their missile weapons, and installing mine rails.

The middle engine and propeller shaft of Tuima and Tuuli were removed during the modernization to make space for the mine laying equipment.

After decommissioning, the vessels were moored at Loviisa, and it was planned that one was to be transferred to the new Maritime Museum in Kotka.

However, in October 2006, the Finnish Ministry of Defence stated that all four were to be sold to Egypt where they were refitted and taken into active service.