This CRL Makita 7" (178 mm) Electronic Sander/Polisher maintains constant speed regardless of load variations, has a pre-set speed setting dial, and a lock-on button for continuous use at one speed. It is lightweight at 6.6 lbs. (3 kg), well-balanced for easy handling, and double-insulated for operator safety. Standard 5/8" (16 mm) 11 UNC spindle. The 7" (178 mm) backup pad easily accepts all seven inch sanding discs.