HP Laserjet 4 free for pickup

You might try Kingston's website. If your printer doesn't come up on their memory selector, give their 800 number a call. I have found them to be unfailingly polite and helpful in assisting me when I want to know what memory will work with something obscure. Some times the answer is, "We don't know." But they've admitted that in a competent way, as opposed to trying to sleaze their way through. And if I can supply some technical details they'll sometimes make an educated guess with caveats. That's how I found the memory module for the Kyocera C170N. There's some info on Kyocera's spec sheet about the type of module used. The Kingston guy didn't have any info on that printer yet, but thought that one or both of two of their modules would likely work. At that point, I had the choice of buying one directly from Kingston with a nice return option if it didn't work, or gambling and buying it from a discounter at a lower price with a less friendly return policy. Jeff Walther