100mm x 50mm (4x2) Timber
 
Avalibable in:  
3m (10ft) - £5.95
3.6m (12ft) - £6.95
4.2m (14ft) - £8.10
4.8m (16ft) - £8.75
 
Strong enough for some applications such as wall plates, rafters etc. 
Mainly used on internal floor joists and roof joists.