The Halda Tripmaster and the Twinmaster were built by Haldex AB in Halmsted, Sweden till 1976 and were the epitome of mechanical tripmeters in times of the famous rallies like the Mille Miglia, Rally Monte Carlo, Tulip Rally, Liege-Rome-Liege, Rally des Alpes, Akropolis, 1000 lakes Rally and so on. Beside stop watches these instruments were most important to the navigator and driver in the cockpit of an Austin-Healey, MG, Triumph, Jaguar and other classic cars. Rally experts like the Morley Brothers, Stirling Moss, his sister Pat Moss together with Ann Wisdom as navigator in Austin Healey, John Gott, Rauno Aaltonen and others swore by the Halda Trip-/Twinmaster.
Today these instruments become increasingly popular as organisers of many Rallies only allow 'historic correct' instruments. The Halda Tripmaster and the Twinmaster as well as the Speedpilot comply with these rules and can therefore be used at these events without hesitation.
In relation to the Tripmaster the Twinmaster has the advantage of two independent controllable counters. With these you can measure intermediate stages by remaining the overall counter reading. One knob controls whether only one of the counter should be active or both. Another advantage is that the knob down left sets the direction of counting (forward or backward). This is very useful in case you missed the right way and have to go back to the last point. Both counters can be zeroed independently. The knobs on the right side of the case provide a possibility to preset one or both figure drums to any number you like.
By changing the gear wheels the Tripmaster and the Twinmaster can be adjusted easily to any model of car and its wheel size. Thus they indicate very precisely (± 1 meter/1,000 meters) the covered distance.
As the Tripmaster and the Twinmaster has not been built for 30 years now, it becomes more and more difficult to obtain a good and mechanical sound unit. Here you have the opportunity to upgrade your cockpit with a nice unit and to score in a 'legal' and sportive way on your next rally.
The Halda Tripmaster and the Twinmaster were built by Haldex AB in Halmsted, Sweden till 1976 and were the epitome of mechanical tripmeters in times of the famous rallies like the Mille Miglia, Rally Monte Carlo, Tulip Rally, Liege-Rome-Liege, Rally des Alpes, Akropolis, 1000 lakes Rally and so on. Beside stop watches these instruments were most important to the navigator and driver in the cockpit of an Austin-Healey, MG, Triumph, Jaguar and other classic cars. Rally experts like the Morley Brothers, Stirling Moss, his sister Pat Moss together with Ann Wisdom as navigator in Austin Healey, John Gott, Rauno Aaltonen and others swore by the Halda Trip-/Twinmaster. 
In relation to the Tripmaster the Twinmaster has the advantage of two independent controllable counters. With these you can measure intermediate stages by remaining the overall counter reading. One knob controls whether only one of the counter should be active or both. Another advantage is that the knob down left sets the direction of counting (forward or backward). This is very useful in case you missed the right way and have to go back to the last point. Both counters can be zeroed independently. The knobs on the right side of the case provide a possibility to preset one or both figure drums to any number you like.
