Substantially sized 13A plug made from flexible white plastic.
The plastic is a slightly flexible type and has yellowed somewhat - although most of the yellow colour is due to greasy dirt on the surface.
Each terminal has the wire colour moulded into the plastic - Green/Yellow, Blue and Brown.
The green colour on the fuse is corrosion, and the entire insides are coated with grease - probably from a kitchen.
The 87 is possibly the production year, and the 'clock' style design above is probably the month as there are 12 positions.