Kryptonite's beefy Stronghold ground anchor provides a permanent locking point for your bike, and can be installed indoors or outdoors. It bolts directly into cement or concrete using three 5/8in anchor bolts.
The 5/16in and 5/8in masonry bits needed to drill the bolt holes are included, along with all the other tools you'll need (except for a drill and safety specs), such as 4mm and 6mm Allen keys, and hardened security balls and cover disks to stop the bolts being unscrewed.
It's simple to fit using the included instructions – although the depth of the holes needed means the drilling can take some time – and can be screwed down tightly enough that it's impossible for thieves to get anything underneath it to lever it out of the ground.
The anchor's 6mm hardened carbon alloy steel shackle lays flat when not in use, making it safe to drive or walk over. It's wide enough to pass a chunky cable lock through.
The Stronghold used to have Sold Secure Gold status – the top rating from the independent testing organisation administered by the Master Locksmiths Association – but wasn't submitted for re-certification by Kryptonite for 2009. The design hasn't changed since it achieved the standard.