Or, more easily, you could just buy one: https://www.kinesis-ergo.com/shop/advantage2/ https://www.kinesis-ergo.com/shop/advantage2/. I've used a Kinesis Advant

Or, more easily, you could just buy one: https://www.kinesis-ergo.com/shop/advantage2/ https://www.kinesis-ergo.com/shop/advantage2/. I've used a Kinesis Advantage at home and at work for 10 years now.