One illustrative embodiment of an end effector generally comprises a tip, a housing, and a main insert. The housing may include a housing neck, one or more housing sections, and an end section. A main insert may be positioned within the housing. One or more intermediate inserts may also be positioned in the housing, as may an end insert. During use, it is contemplated that the end effector will provide a user a more ergonomic and comfortable experience, requiring less effort from the user resulting in a less fatigue during use. Additionally, the illustrative embodiments of the end effector may be adjusted for optimal use in an infinite number of applications. Additionally, the locator ensures that the user properly locates the distal end of a rivet to create a uniform nugget as the distal end of the rivet is spread.