9.5 metre Xmas lights, flame effect (Teignmouth TQ14)

A string of 20 lights, separated from each other by about 50 cm, for a presumed total length of 9.5 metres. (Then there's a further 2.5 metres of cable leading to the mains plug.)

The lights glow orange and flicker to give a flame effect. There are only 17 working bulbs. There's a sticker near the plug which implies the bulbs are replaceable. No instructions or packaging.