I have only just fitted it with great difficulty in a very confined space so cannot commnt upon durability but the Sea Panther diesel in my boat started immediatley. There is metal band at the electrical contact end which is there presumably to keep water and dirt from the inside of the starter which if you are in a tight space makes fitting even more difficult but I would imagin that being in a river boat environment the conditions for the starter are much less hostile than being exposed to water and grit when fitted to a mini car or similar.