See this link:
This panel has been re-designated as LC3040B. It is a 150 amp, 30 space , 40 circuit panel. That means that it has 20 slots that take full size breakers only and 10 slots that takes half size breakers.
http://www.munroelectric.com/silvereclipse/index.jsp?path=product∂=1774&ds=dept&process=search&ID=,Breakers..Panels...Gear,Loadcenters.,Murray...Siemens.Panels,Main.Breaker.Loadcenters
This panel has been re-designated as LC3040B. It is a 150 amp, 30 space , 40 circuit panel. That means that it has 20 slots that take full size breakers only and 10 slots that takes half size breakers.
http://www.munroelectric.com/silvereclipse/index.jsp?path=product∂=1774&ds=dept&process=search&ID=,Breakers..Panels...Gear,Loadcenters.,Murray...Siemens.Panels,Main.Breaker.Loadcenters