A pair of 15A relays which can be used to protect column switches in all 105 GTs and Series 1 and 2 spiders. Avoids having the column switch control a heavy current load which can burn out the contacts.
Please see the 3rd image for a wiring diagram.
Note, some US-market 1750 and 2000 GTVs already have a relay governing the inner headlamps, so please check before ordering.