On the picture you can see Roger Waters posing with a Kubicki Ex Factor bass. This picture looks like one of the publicity photos made around the time of The Wall live in Berlin concert (1990), unfortunately, I haven't found any other info or any videos of him playing this bass so maybe he was just posing with it. According to Philip Kubicki - designer and manufacturer of the Ex Factor bass - he hasn't had any dealings with Roger Waters or his staff, suggesting that this bass could be a one of those made by Fender under a licence between 1988-91.

Also, Andy Fairweather Low can be seen playing a red one at The Wall in Berlin concert on Another Brick in the Wall, pt. 1 and Run Like Hell. Roger often lets members of his band use guitars and basses out of his own collection, so it's possible that Andy's Kubicki bass belonged to Roger.

Anyway, I would say that this Kubicki Ex Factor bass is a perfect match to David Gilmour's Steinberger guitar of the roughly same period, so here are some details and specs:

The Philip Kubicki Ex Factor Bass is so named because of the extended string that allows the “E” string to be “D” tuned without changing string tension or having to transpose. The patented string clasp, when released, gives access to the D# and D notes. Going from D to E is accomplished with a flick of the thumb. The standard head-mounted tuning keys were replaced by the patented body-mounted tuner. Factor basses are all fitted with proprietary humbucking pickups and circuit board. The 18 Volt circuit board has a stacked volume/pan control, a bass/treble control and a six position rotary switch that allows the player to select from a standby position through two active settings and three passive preset positions. The neck is made of 32 sheets of rotary-cut Eastern hard maple and an ebony fingerboard. The fingerboard has jumbo frets and a 7 1/2" radius.

Nigel John Taylor used the Kubicki Ex Factor as his main bass from 1985 to 1990, as shown in a user-uploaded photo on BlogSpot.

At minute 1:16 you can see Zeta playing an Ex Factor bass. He used it a lot in the 80s.

Stu can be seen playing a blue Kubicki Ex Factor bass at 0:03 in this video.

Sean Malone used the Kubicki Ex Factor bass during the "Focus" era. It can be seen in different videos of live shows of the band.

In this video, in 1:41, at the background is seen this factor bass

In an interview with Guitar Gear, Paco Huidobro showcases the Kubicki Ex Factor bass guitar as part of his collection.

In the video "Halibour Fiberglass Sereneiders - Bailando en la sociedad rural" on YouTube, Javier Malosetti is seen playing a Kubicki Ex Factor bass.

on the 1987 Whitesnake album I partly used a Kubicki Ex Factor bass

JT started out with Aria basses but beginning in 1985, he was seen at shows playing his new Kubicki Ex Factor bass. He played a white one at the 1985 fundraiser concert 'LIVE AID'.

Bi Ribeiro is seen with his iconic Kubicki Ex Factor bass guitar in a photo from Jotacidade, highlighting its status as his most traditional instrument.

He also advanced me some money before the tour so I could buy my Philip Kubicki four-string