First of the Z1 series... therefore not named with a "Z" :)
An unfortunately xxx-rare turntable and the original model for the well-known PL-L1000 : same Stable Hanging Rotor, same arm structure, same carbon-loaded materials, same black looks... only the PL-L1 weighted 26kg !
Placing the bearing under a very small shaft and almost at platter level, the Stable Hanging Rotor was a Pioneer staple from the Exclusive models to the equally successful PL-50L and PL-70L/LII.
Accounting for the L1's rarity might be, market-wise, the slightly earlier but extremely successful Exclusive P3 - and linear-trackers, however lavishly engineered, never did really cut a groove... in the market.
The L1, however, like all of Pioneer's "1" units (CT-A1, C-Z1, M-Z1, H-Z1, P-D1) is an extreme good-looker and I sure wish I could find out if its sonic qualities were on the level of its design !
You can refer to the PL-L1000 post of this website for the details of the tonearm and SHR as it is the same theory.
A real PL-L1 here.