Startrite Mercury 5 Drill Chuck Options:
BO2598 – This is a classic style keyed chuck, similar to what would have been originally fitted to the machine. It comes with a chuck key.
BO2598/A – This is the newer keyless chuck upgrade. Simply twist the chuck to loosen or tighten the chuck, similar to many popular modern hand drills. This chuck upgrade is especially useful if you are having to swap drill bits frequently, it’s much faster and simpler to do compared to the keyed chuck version.

