When there was a grip part such as rubber, when oil adhered it was hard to take and it was sometimes melted, so I was looking for something without a grip part. Although it is shorter in length than usual, there is no need to write it with minimum length necessary. Even if put in the pants pocket, it is difficult to get in the way of bending and standing posture. Although it is not thought that replacing the core is made, when it runs out, the body also gets damaged so you do not need OK as yourself OK. It is even better if there are 2 color or 3 color version.