Replacement balls for Perixx 34mm trackball mouse, a great value set of 2 with different types. * Black (Standard Type): Total usage time approximately 2 days. No noticeable scratches or stains, in good condition. * Red (Matte Type): Total usage time approximately 1 week. Also no noticeable scratches or stains. This set allows you to try different textures and operational feels, so you can choose according to your preference. Also recommended as spares. ※ Please refrain from purchasing if you are concerned about minor scratches, as these are used items.