Inventories

Inventories are stated at the lower of standard cost (which approximates actual cost on a first-in, first-out basis), or market. Inventories consist of the following (in thousands):



	October 1, 2011		January 1, 2011
Raw materials and sub-assemblies	$	22,554	$	22,352
Work in process	15,418		10,295
Finished goods	13,381		10,521
Total inventories	$	51,353	$	43,168

Total amortization expense for demonstration tools for the three month periods ended October 1, 2011 and October 2, 2010 was $0.4 million and $0.5 million, respectively, and for the nine month periods ended October 1, 2011 and October 2, 2010 was $1.2 million and $1.1 million, respectively.

The Company reflects the cost of systems that were invoiced upon shipment but deferred for revenue recognition purposes separate from its inventory held for sale as “Inventories—delivered systems” in the Company's Condensed Consolidated Balance Sheets.