Halfords HB202, clamp in the original position, +ve post to the front and beside the tunnel: (Bottom Gear Bob)

Yuasa YBX5202 same size, 30% more capacity, same post orientation:

Yuasa YBX3102 same size, same (lower) capacity as the Halfords, but the post orientation the other way round which may be a factor in the length of the 12v cable: (David Baram)