As explained in the manual tech tips, the jib car's thumbscrew sticks up and causes all kinds of problems: ripped clothing, snags uncleated jib sheet when it shouldn't, etc. One recommended procedure was cut off the thumbscrew's head and then cut a slot. That way, you could use a screwdriver to adjust the jib car position, which they say is rarely, if ever, done. I'm lazy. At a good hardware store (in San Diego's "Miramar" area: Marshall's Hardware 858-271-5555) I bought two set screws. They are 3/8" diameter, 24 threads per inch, 3/4" long, $1.25 each. Ideally, the parts should be 316 stainless steel-- I've heard that's the best grade and won't rust. The parts I found may be the next best thing- 318 S.S. My store told me 316 SS is hard to find. I put a little anti-seizing compound on the threads. A disadvantage of this approach is that an allen wrench is needed, whereas anybody with a swiss army knife or flat head screwdriver could adjust the other style. Will water collect and cause rust in the allen socket? How will 318 SS look in a year? Will the threads seize? I dunno. Low cost, low effort and a really clean appearance made this seem like a good idea, but we'll see.