Peco IL120 chair and Pin Hole Drilling Aid. 
Helps ensure you don't damage the sleeper by drilling in the wrong place, and helps straighten the hole you drill.
Simply place the aid over the sleeper, and drill your hole, in the centre, and straight. Move to next and repeat quickly and reliably. 
Has been tested on Flex Track Sl-108F Bullhead code 75 track.
Hole suits up to a .8mm drill bit. There is nothing stopping you drilling it bigger. 
It does not matter if you have spaced your sleepers out, as it uses the sleeper it is drilling to, to align. 

Any questions please ask. 

If you have need for other track size let me know, it can be custom made. 

Colour of item may vary. Black specifically available on request with message to buyer at time of purchase.