Seed Anatas Eraser
The idea behind the Seed Anatas eraser, with its 15 holes and 20 rugged grooves, is to provide precise erasing through the life of the eraser ("Ana" means hole in Japanese.) Plastic eraser has a stiff plastic protective sleeve which you can either extend the eraser from or remove completely. SEED is a Japan-based firm that's been manufacturing erasers for over 100 years.
.75 x 2""