I bought my first pair sometime in the 80’s, might be earlier. You fit them to the cranks, press down with your feet and the bike goes forward. After a hundred or so miles you take the little cap off the end, there is a spanner you buy separately for that, and fill the cap with grease and put it back on. Ride some more and repeat. After a while dirty, emulsified, grease (which is bad for the bearings) comes out the other end. Clean it off. Do this and your knees will wear out long before the pedals do. I have found a better pedal but it’s five times the cost of these and the cleats to hold the pedals to your shoes are twice the price of the pedal as well. The 1lb tub of grease I use on these pedals was bought in ‘96.