Review on Hydraulic Brake Lever Master Cylinder Sight Lens 18mm - (Set of 2), Premium Replacement Kit with O-Rings by Precision Auto Products by Ken Barnett

Works great but you will need 2 because like me you break one you will need the second, it fits my 86 Honda Shadow 500 and leaks but doesn't I'm not saying you shouldn't try this installation method. The best way to avoid bending the sight glass body is to use a block of wood and a vice. I used a c-clip and a block of wood to make sure it went in evenly and once it was in I took the block out, covered the scope with a rag and laid the c-clip down the way you rotate it. but only the side that is flat and you will feel the pressure and then it does it the way they say with the socket and it doesn't work hitting it all it does is that to bend whole. Use a C clamp and you'll get it working just fine with no leaks.