Grinder for windshield wipers

A grinder for a windshield wiper, the grinder comprising:

• first and second plates each comprising at least one bent portion, a sandpaper side and a finger side opposite to the sandpaper side, with the bent portion extending at an acute angle from the sandpaper side;
• and
• first and second pieces of sandpaper attached to the sandpaper sides of the first and second plates, with the first piece of sandpaper attached to and extending from the bent portion of the first plate to the sandpaper side of the first plate and the second piece of sandpaper extending from the bent portion of the second plate to the sandpaper side of the second plate, wherein the first and second plates are connected to each other, with the sandpaper side of the first plate parallel to the sandpaper side of the second plate and so as to form at least one V-shaped structure by the bent portions of the first and second plates for receiving a tip of a rubber strip of a windshield wiper, with the sandpaper sides of the first and second plates sandwiching the first and second pieces of sandpaper together, and with the first piece of sandpaper attached to the sandpaper side of the first plate facially abutting the second piece of sandpaper attached to the sandpaper side of the second plate when the first and second plates sandwich the first and second pieces of sandpaper together.