[Plodder]

Can someone tell me the size of bolts/pins they used for the tool they've made to hold the crankshaft pulley whilst the retaining bolt is removed?
Also how far the pins have to stick to engage fully in the holes
I want to make a tool in preparation for changing the Cambelt next year as it will be difficult for me to make the tool once the car is disabled by being up on jacks as I have limited work space in my lock-up garage
Thanks