A linear actuator especially for adjustable furniture comprises a spindle with a spindle nut for bringing about the adjustment of the article of furniture. The label is formed by first providing a ribbon of labels with at least one folded over portion and then subjecting the folded ribbon to heat and pressure to set the fold. The compressible middle layer is made of a thermoplastic elastomer material that can compress upon impact and return substantially to an original shape of the headgear after the impact has ended. Design pursuant to the trapezoidal optic reflector pertaining to the invention can substantially reduce space required of Light Track in an optic system, and therefore commensurably volume and weight claimed in the entire optic system, which facilitates compact design of the products and installation of other devices or utilities in the space so saved in the entire optic system. A memory stores interrupt information indicative of a status of execution of the first job when the interrupt occurs.