د.ك (Kuwaiti dinar), KD (Kuwaiti dinar).
Central Bank of Kuwait

The Kuwaiti dinar is the currency of Kuwait. It is sub-divided into 1,000 fils. As of September 2019, the Kuwaiti dinar is the world's highest-valued currency unit per face value.

The dinar was introduced in 1960 to replace the Gulf rupee, equal to the Indian rupee. It was initially equivalent to one pound sterling. As the rupee was fixed at 1 pushing 6 pence, that resulted in a conversion rate of 13 1⁄3 rupees to the dinar.

When Iraq invaded Kuwait in 1990, the Iraqi dinar replaced the Kuwaiti dinar as the currency and large quantities of banknotes were stolen by the invading forces. After liberation, the Kuwaiti dinar was restored as the country's currency and a new banknote series was introduced, allowing the previous notes, including those stolen, to be demonetized.

You will receive just 0.30 Kuwait dinar after exchanging 1 US dollar, making the Kuwaiti dinar the world's highest-valued currency unit per face value, or basically 'the world's strongest currency’.