E-Switch is an American switch manufacturer.
KS1100 is a “series” of computer keyboard switches, although it only contains a single model (E-Switch have confirmed that there is only one part number in that series). KS1100 is a clone of Cherry MX, specifically MX1A-11NN (plate-mount MX Black). KS1100 is rated for 50 million cycles at 10 mA and 12 V DC.
The single model KS1100OA1AF060 denotes a KS1100 switch, momentary (OA), SPST (1), 15.2 mm height from PCB to keystem top (A) and 60 gram operating force (F060).
KS1100 was announced on E-Switch’s blog on the 9th of August 2017.
All indications are that KS1100 is unbranded.