Shares
£m
Sundry
investments
£m
Total
£m
Cost
At 1 January 2014400.00.6400.6
Disposals(0.6)(0.6)
At 31 December 2014400.0400.0
Provision for impairment
At 1 January 20147.47.4
At 31 December 20147.47.4
Net book value
At 31 December 2014392.6392.6
At 31 December 2013392.60.6393.2

The sundry investments relate to the Bodycote Investment Incentive Plan, as explained in the Board report on remuneration.

Details of principal subsidiary undertakings of the Company are shown in Principal subsidiary undertakings.