The bolts that are needed for all of our holds, we can supply these in either 50mm, 70mm or 90mm. If ordered at the same time as holds please contact us so that we can ensure we send you the corrrect lengths for the holds you have ordered. The drive on these bolts is a 6mm hex bit (allen key). These are high quality zink plated 8.8 high tensile bolts...in other words, just the job.