An elderly couple in Uttar Pradesh's Aligarh have made what they claim is the world's biggest lock. The lock, which weighs over 300 kgs, has been made with iron and brass. It measures 6 feet 2 inches in length, and is 2 feet, 9.5 inches wide. The couple has also created a key to match the lock, which weighs close to 12 kg and is 40 inches long.Satya Prakash Sharma and his wife Rukmini have spent one year creating it and incurred a cost of close to one lakh rupees.