They do a few versions, rack mounted like the picture has side entry cable, maybe not ideal for dropout mounted. The 'seatpost' mounted type the cable comes out the back, but its quite a beefy rubber grommet on it, to prevent cable damage. I'm getting the latter, in the post my way just now.
If you've got a full mudguard then you've got a few options of places to put it, get creative with bits of old stainless/alloy bracket and bolts!
They do a few versions, rack mounted like the picture has side entry cable, maybe not ideal for dropout mounted. The 'seatpost' mounted type the cable comes out the back, but its quite a beefy rubber grommet on it, to prevent cable damage. I'm getting the latter, in the post my way just now.
If you've got a full mudguard then you've got a few options of places to put it, get creative with bits of old stainless/alloy bracket and bolts!