.A mouth prop (also bite block) is a wedge-shaped implement used in dentistry for dentists working with children and other patients who have difficulty keeping their mouths open wide and steady during a procedure, or during procedures where the patient is sedated.
2.The bur chuck is designed to be used with small burs and mandrels as long as they do not exceed 1/4 inch diameter.
3.it is to be used with lathes that have a tapered shaft.