The 700 series is the industry standard and a popular choice by OEM builders and marine electricians globally. The standard isolating switch is the 701B while the 701S is the selector switch of the same size. The 700 switch is BEP's special "Easyfit" model.
It can be surface mounted or fitted through a panel of up to 19mmand attached with the threaded ring. 
Spare keys are also available for each model.