Pentium class motherboards access memory in 32 bit words, so you have to use this type of module in pairs. 30 pin SIMMs also exist, but are not used on current motherboards. The 168 or 184 pins of this package allow for 32-bit access. You can therefore install these modules individually on a Pentium class motherboard. Unfortunately, laptop memory is even less standard than desktop.
Some laptops use SIMMs, some DIMMs, and many use proprietary memory cards.
In general, never buy a laptop memory module that does not explicitly state that it is for the model or series of your laptop. This configuration has just enough chips to do the job. This configuration has one extra bit per word. If this bit does not add up correctly, a parity error has occurred and the system is halted to prevent data corruption. This configuration has enough extra bits per word that if a single bit is incorrect, the motherboard can figure out which one is wrong and correct it.