Cutting blades are disclosed for use with a rotary trimmer head assembly with one or more swiveling blade receptacles, where the receptacle has a cylindrical body which defines a passage therethrough for a trimmer blade. The cutting blade preferably has a connecting end portion defining a blade mount aperture adapted to receive the swiveling blade receptacle. A male plug connection member is disposed within the blade mount aperture and preferably has bowed spring arms which are resiliently inwardly deformable, which are urged inwardly upon insertion into the female blade receptacle. The spring arms flex outwardly upon passage through the female receptacle. A multitool retention device is disclosed having a mount aperture end adapted to receive the receptacle and a tool retention end comprising at least one tool retention arm defining an elongated retention slot configured to slidingly receive and retain at least one tool member having a flange at one end of the tool member.