Part of the efforts to keep LP turntables selling although CD already was on its way to grand success, the Flamingo was in the higher side of things with a Quartz-Locked direct-drive motor, built-in phono EQ and a linear tracking tonearm - far from the PRP5, AT727 or even the pretty PS-Q7.
The big one, PS-F9, sports a motorized clamping system (behind the Sony tag), a magnificent slightly off-white finish with pearl-like coating (now you see it, now you don't - but you never see it in Sony's own images), a pair of mini-jack headphones' outputs, a built-in cleaning brush next to the tonearm and, for the JP models, like the PS-Q7, an FM transmitter (but without a LED-lit antenna) ; the Line-Out mini-jack circumvents the volume ring.
The PS-F5 is the more common and simplified version : no quartz-locking, no FM transmitter, no line-out and only manual disc clamping. And no pearly-white finish coating either ; that coating had a long-term side effect effect : F5s yellow a lot, F9s don't.
Both are to be operated with batteries but optionally provide a jack for 6V DC power source ; they can be used horizontally, vertically or even hung on a wall.
A LED dot facing the headshell allows to see where the arm actually is (plus battery power display), something which Technics never even thought of implementing... The retractable feet are very much part of the charm of this quite perfect design.
The serial number sticker, inside the battery compartment, reveals a 5-digit system often used on Sony's in-house but "special" products.
The packaging (kraft-cardboard at first, then white, both with two-tone red imprint) wasn't as clever and elaborate as that of the PS-Q7 but after all, unlike the latter, the Flamingo was portable on its own.
Sony sold manymanymanymany F5s and manymany F9s but they are both rather rare today. I have an F9, it works very well (stable speed, decent noise floor) and I'll never ever let it go.
A clean description of the F9 here ; a dedicated website here (with safety instructions regarding the 6V input), Sony's own completely bland page here and a small view of the early packaging here.