The most common type of hamster cage has a plastic base and a rigid wire top. The wire top can be unclipped from the base making it easy to get the hamster out of the cage or to clean the cage.
Similar cages with two or more floor levels are also available with ladders which allow the hamster to climb up and down between the different levels.
These plastic base, rigid wire top cages are lightweight, durable and relatively cheap. However, the secureness of any doors on such a cage should be checked as any door that is opened too easily may be pushed open by the hamster.
A cage with a shallow base will allow wood shavings to be easily kicked out of the cage and so it is best to find a cage with a deep base. The disadvantage with these type of cages is that they are not draught proof and so it is important that this is considered when deciding where to put the cage.
For housing dwarf hamsters the bars on these types of cages should not be spaced more than 0.5 cm apart to prevent the hamster from escaping by squeezing through the bars.