Givi Box Size For CB1100?

[widude]

Hello, I have the Givi rear rack in the pipeline, next in line with be a rear, top mounted luggage case/box.

I'm thinking about the 'Monokey' box from Givi, just looking at sizes. I may also include a backrest for the box, for the occasional passenger.

They have the 33 liter size that fits about one helmet, about 16" wide I think. In the past I would just use a backpack if I wanted to pick up a few items. I'm not really looking to pack up and hit the road with this. It's more for going to pick up a few oil filters, or other smaller items. I don't want an out of per portion larger box than needed.

For medium use, is that about the right size for the CB? I'm not home now but could do some measurements to see how sizes stack up. Just asking about others that may use that or a similar box.

Any other directions a guy should go with rear carry? Thanks