Levelok leveler with 2 base attachments will provide safety on uneven surfaces. Base units stay attached to the ladder while leveler can be easily removed when not in use. Swivel shoe with ice pick on both ends mount securely to the surface. Leveler can be used on either side of the ladder. Provides up to 8 1/2" of travel adjustment. Designed to be used with the MT series and can also be used on Werner model