The ets systems in the uk use hitag s chips they are a read only chip so you can not write anything onto them to stay permanent.,so lot number can be changed The ets chip when put into a magnetic field is energised and the read part of the landing board reads the chip code and passes this code to the ets base ,the base is programmed to only interpret in the case of unikon ,only chips that start with c9. If the chip does start with c9 then the base looks into its pre programmed memory ,that secretary has done,and matches chip complete number to any in bas memory and hey presto your red cock su20av1111 is matched and clocked . So if you cannot positively get chips starting with c9 they will not work unless unikon put out an update to make their clocks open clocks and they wonâ€™t do that ,but any new clock manufacturer to try to sell might at first use open clock until sales are depleated then close them up to run the business. On ring sales only. Each ets manufacturer are now staying in business on mainly ring sales and provide support to us ,if they go bust who will repair them ,provide updates for smooth running ,so they are a nessesary evil until membership drops to zero and all we do is send to one loft races.