Wholly aromatic synthetic fibers spun from liquid-crystalline polymer solutions, having a crystal size of not greater than 50 and an ionic substance content of no more than 1. , the ink comprising: at least two monofunctional acrylate monomers which comprise a cyclic monofunctional acrylate monomer and 2-ethyl acrylate; a monofunctional monomer selected from an N-vinyl amide, an N-acryloyl amine or a mixture thereof; a multifunctional acrylate monomer; a polymerisable acrylate oligomer; a radical photoinitiator; and a colouring agent. In this deep sleep mode of operation the mobile device periodically samples the RF conditions and gradually increases the period between samples when the RF conditions do not improve. In the state in which the cam shaft 20 is securely retained between the cylinder head 40 and the rocker case 50, the axial displacement of the flange portion 31 is restricted by the groove 51. The compression chamber is operatively connected to a gas volume to be compressed upon displacement of the chamber wall element. A separate spring retainer clip is also provided, which secures the hub cap to the hub body.