Listing is for a  Set of 4 Glow-Plugs These are manufactured  by Beru
one of the foremost manufacturers of Automotive components to the Industry
and is one of if not the Leading supplier of O.E glowplugs
Quite possibly these are the plugs that were in the car out of the factory
Specifications and applications are below, although the table is pretty accurate
If in doubt please ask and we'll see if we can run the reg number through.

Part Numbers are 
0100226208 ; 947 MJ ; GV 947
Spec
Voltage (V) 11 /  Port Type  M4/2Nm  /  Cone Pitch 119  /  Thread Size M 10x1,25  Overall Length (mm) 85
Spanner Size 12 mm  /  Tightening Torque (Nm) 1-5  /  Rated Current (A) 6  /  Fitting Depth (mm) 19  /  Failure Moment (Nm) 35

Suitable for the vehicles listed below ( please read above )

VAUXHALL ASTRA
Saloon1.5 DT1499cc4cyl.53kW01/87 - 08/89
Saloon1.5 DT1499cc4cyl.49kW01/88 - 08/90
Estate1.5 DT1499cc4cyl.49kW01/88 - 08/91
Estate1.7 TD1686cc4cyl.60kW12/91 - 02/98
Hatchback1.7 TD1686cc4cyl.60kW12/91 - 02/98
VAUXHALL BRAVA
Pickup3.1 D3059cc4cyl.80kW07/91 - 07/01
VAUXHALL CORSAVAN
Box1.5 D1488cc4cyl.37kW08/94 - 12/95
VAUXHALL MIDI
Bus2.4 TD2380cc4cyl.56kW09/94 - 08/97
VAUXHALL MONTEREY
Closed Off-Road Vehicle3.1 TD3059cc4cyl.84kW09/91 - 07/98
VAUXHALL NOVA
Saloon1.5 TD1488cc4cyl.49kW01/90 - 02/93
Hatchback1.5 TD1488cc4cyl.49kW01/90 - 03/93