28500 Features: -Micromot rotary tool 50.-Specially balance motor allows tool to run smoothly.-Use with Micromot transformers of at least 1.0A.-Load speed: 20,000 rpm.-Transformer NG 5/E power supply.-Speeds adjustable between 5,000 and 20,000 rpm. Options: -Available size: 0.39", 0.52", 0.78", 0.93", 0.109" and 0.12". Dimensions: -Overall dimensions: 1.57" H x 11.4" W x 6.49" D, 2 lbs. Warranty: -Manufacturer provides 2 year limited warranty.