Tool Kit, Rotary Scraper, 3-Piece, Tools for 500mL, 1L and 2L Round Bottomed Flasks. Easily remove dried-on solids from the interior walls of round bottom flasks without scratching or harming your flask!Chem-spin scraper tools provide an easy method of removing the majority of desired, dried-on solids from the interior walls of round bottom flasks. Motor driven, the spinning chain rapidly and effectively brushes the surface as the loose solids collect on the bottom. Minimal physical effort is required. Tedious, time-consuming, manual scraping with a spatula is eliminated.Tool Kits include selections of rotary scraper tools only.