A simple vertical transducer pole we made for my workmate. The aluminum pole is 25mm outside and is only 1.3mm in the wall. this is made for his lowrance hook reveal so he can use it on his 3 boats and have it very portable. the pole holder is for a mountainbike with part number 27-1948 on the swedish company biltema , the bushing is to convert the big hole with diameter 28.6mm to fit the 25mm aluminum rod