Rubber insert part number is M980001814 £2.49 from H.R.Owen for 4200 Mas two button.
As a 4200 Mas owner my circuit board in my one and only key fob died which controls the central locking and alarm.the circuit board part number S 4633 Two button and I could not switch the alarm off which gave me a head ache.
As most 4200 are fitted with the Meta M826 alarm system I had the the alarm ECU and my dead circuit board sent to Abacus car alarms in London they re coded the ECU and two and two separate key fobs and let me have their last Maserati S4633 circuit board for my mas key at a good price.
I now have a fully working Maserati key and two spare fobs programmed so my problem will not happen again
They did tell me I was very lucky in obtaining the above board because Maserati has put the blockers on these boards being sold separate I wonder why could it be the kit will cost £1.400 plus vat. ouch..
The lads at Abacus can do everything else but supply the above circuit board S4633 cos I pinched the last one..
I am now on the hunt for a compatible spare key..checking out China,