Plagued by unwanted phone calls from double glazing salesmen computer generated calls silent calls fax calls and more youll welcome this nuisance call blocker compatible with all domestic phone lines even those with broadband this call blocker is pre programmed to block some 200 rogue callers known to the call prevention registry you can add 100 numbers to its memorypre programmed with all rogue numbers kwown to cprblock now push button blocks unwanted callers permanentlyblocks inte