Sds-plus bits have grooves on the shanks that lock securely into the chuck but allow the bit to move back and forth independently of the chuck. Some of the really big rotary hammers like dewalt 3 mode sds-plus hammer, D25033K have a similar system, but larger called the sds-max. You can use dewalt 3 mode sds-plus hammer, D25033K for concrete forming, fencing erectors, domestic air-con installers. Its 3 mode function, powerful motor and ergonomic design will make your job easy in the construction site.