These stems have always perplexed me. Sold by Wald in at least two versions the No.4 was the thin one like being reproduced here and the No. 5 was the fat one. The only bike I'm aware of that used this stem from the factory was the '39 Manton Smith Golden Zephyr. That said it seems like every Shelby Airflo Speedline/Arrow you see is fitted with these stems even though they didn't come from the factory with them. I'm looking forward to seeing the bikes the members who are buying one of these put them on. V/r Shawn