1,200 foot pounds in reverse. 1/2" air coupler.  We have an adapter to go to a 3/8" coupler.  No smaller though, gun will not work properly, it would be like strangling a opera singer and expecting them to sing. 3/4" drive. Pistol style grip. 1,000 impacts per minute.  Minimum of a 10 cfm compressor.  In air compressors, the abbreviation "CFM" stands for cubic feet per minute, a measurement of the flow rate of a volume of air (not to be confused with "psi"). When using an pneumatic-powered tool connected to an air compressor, each tool has a minimum "CFM" rating for optimal operation.