Horstmann, Switch, models:

425 Coronet	User Operating Instructions Manual
425 range	Installation Instructions Manual
CentaurPlus C11 Series 2	User Operating Instructions Manual
CentaurPlus C17 Series 2	User Operating Instructions Manual
CentaurPlus C21 Series 2	User Operating Instructions Manual
ChannelPlus H11XL Series 2	User Operating Instructions Manual
ChannelPlus H17XL Series 2	User Operating Instructions Manual
ChannelPlus H27XL	User Instructions
ServicePlus S11	User Operating Instructions Manual
ServicePlus S17R	User Operating Instructions Manual
ServicePlus S21R Series 2	User Operating Instructions Manual