This is a good example of a timer from Omega retailed through Prestons as noted on the dial. Prestons were long-standing agents for Omega in the UK and probably their biggest distributors of timers until their closure in 2016 after almost 150 years of trading.
Each minute is divided into 100 equal parts so it would have been intended as a "process" timer as in "Time & Motion" or "work-study". Sub counter times to 30 minutes. The watch is crown wound. The slider button on the side starts, stops and restarts the timer. The crown resets it. All works exactly as it should. The dial is in unmarked condition. Some of the black finish has been scuffed of the bezel between 40 and 60. There is some residue on the case-back from a sticker.
Inside is the Omega 8300 calibre movement. Marked Omega 7 jewels there is a Maltese Cross stamped under the balance wheel which denotes that the movement was in fact made by Lemania for Omega (as most of their timers were). The movement is in pristine condition.
Comes with the original Omega Box which is in excellent condition.
1970s omega Decimal Timer
Year 1970s Case Metal Metal Back Metal Metal Back Type Snap Diameter* 50 Power Manual Calibre 8300
*mm excluding the crown and slider