Security Anchor Bolts x4 M10 COUNTERSUNK & security ball Inserts & Key 

Contents:

4 X M10 x Replacement Ground Anchor Security Expansion Bolts COUNTERSUNK. 

Security Ball Bearing Inserts.

Allen Key.

These will fit bolt down security anchors with a hole diameter of 11mm to 12mm 

Also available in sets of two.  see my other listings.