The Shimano ST-RX815-L/ST-RX815-R Hydraulic Disc Brake dual control lever features raised hood heads and recessed finger notches to prevent hand misalignment and slippage. It has an anti-slip texture and brake lever coating, improved braking input performance, higher brake lever axis and a curved brake lever.
All of the above should provide you with everything you'd need on a gravel ride - the right grip and confidence to tackle the choppy surfaces and descents and low-effort braking to prevent fatique on those long, hard rides.
Like the other Di2 hydraulic disc shifters, each dual control lever features two e-tube ports and no remote-shifter e-tube port. It also doesn't have a 'hidden' button on top of the shifters.