| Thatcham alarm car categories are C1 for alarm and | | | | L2 immobiliser. Thatcham alarms for motorhome have |
| immobiliser and category C2 to 1 for alarm upgrade | | | | additional inputs for sensors such as; PIR to protect |
| designed to integrate with an existing C2 immobiliser. | | | | the interior with separate ultrasonic sensor in the cab, |
| Soft top cars should be fitted with a microwave | | | | bike and gas bottles loops, locker, door and window |
| sensor rather than an ultrasonic sensor to protect | | | | sensors. |
| the interior when the top is down. Some of the best | | | | Motorcycle Thatcham alarm categories are MC1 for |
| known Thatcham alarms for cars are from Avital, | | | | alarm and immobiliser and category MC2 to 1 for |
| Clifford, Cobra, Gemini, GT, Toad and Viper | | | | alarm upgrade designed to integrate with an existing |
| Van and Light Commercial Vehicles Thatcham alarm | | | | MC2 immobiliser. Thatcham alarms for motor bikes |
| categories are; L1 for alarm and immobiliser and | | | | are more compact with better waterproofing than |
| category L2 to 1 for alarm upgrade designed to | | | | car or van alarms |
| integrate with an existing L2 immobiliser. Thatcham | | | | HGV Thatcham alarm Heavy Goods Vehicles |
| alarms for vans may require additional doors sensors | | | | categories are H1 for alarm and immobiliser and |
| to be fitted in the cargo area if there is no courtesy | | | | category H2 to 1 for alarm upgrade designed to |
| light switch as all doors need to be covered by the | | | | integrate with an existing H2 immobiliser. Thatcham |
| alarm. | | | | alarms for heavy goods vehicles are a higher voltage |
| Motorhome Thatcham alarm categories are also L1 | | | | then car alarms and the immobiliser is designed for |
| for alarm and immobiliser and category L2 to 1 for | | | | diesel engines. |
| alarm upgrade designed to integrate with an existing | | | | |