You can select e.g. a horse as mount, or you understand it as “select amount” 
Does that guide help?
To create a tx, the OP of the corresponding FLOT thread (in this case: FLOT US-NBT Operations (sell side)) has a lot of information, e.g. the redeem script including a link to Cointoolkit.
Creating a tx on Cointoolkit on mobile phone is…
…no fun.