If you're looking for a maintenance free and non-spillable battery for your bike, the AGM Platinum II battery by BikeMaster® is for you. Manufactured from absorbed glass mat that captures electrolytes, these batteries have a longer storage life and higher performance than standard wet batteries.
Several of us were looking for a modern, sealed, battery to replace the old-style lead acid units in our 1971-72 Honda SL350 K1-K2 motorcycles. While this battery (MS12-5-3B) isn't listed as fitting the Honda SL350, it's dimensions are identical to the traditional 12N5-4B, it's it fits perfect and has the same amp hour rating as the old lead acid battery. The only difference is that the positive and negative terminals are reversed on the MS12-5-3B compared to the 12N5-4B, but there is plenty of slack in the wiring harness on the SL350 to remedy that. This battery has the great quality and fit & finish you expect from a Bikemaster battery and like other Bikemaster AGM batteries I've had in other motorcycles, I have no doubt it will last many, many years.