Yep. Coolheat. If your bike shop ain't lazy, they can order one. HOWEVER !!, there are two different internal thread diameters. The older model cranks have a thicker shaft, with a smaller internal thread dia. The newer cranks have a thinner walled shaft with a larger ID. You will need to specify the right size. KCNC do a bling alu. one in different colours. (although Paragon don't always stock) That is the 'thing' he is referring to. The 'cap' is the crank arm fixing bolt. It is there for an important reason. It sets the correct torque between the left crank arm and the bearing in the BB. Without it you can not tighten the crank arm onto the shaft properly. Step 1. Place right (drive side) through the BB. Step 2. Orientate left crank arm onto shaft splines. Step 2a. Good smack together with your palms. Step 3. Place crank arm fixing bolt into threaded section, and tighten using the tool (shimano, BBB, Park) to 'decent thumb strength tight'. (0.7 to 1.5 N.m to be exakkery) Step 4. Push the plate between the pinchbolts down into its seat. Step 5. Tighten the pinchbolts incrementally and evenly- a bit for one, a bit for the other until tight - 14 N.m To the poster who said it ain't necessary, and to the bike shop who said it ain't necessary..............well now, why do you think Shimano bothered to include it in the box?? NUBBINS.
