(Adds latest strikes launched by Israel against Iran)

Oct 26 (Reuters) - Israel has multi-layered air defences

against attacks by regional adversaries such as Iran, where

military sites were hit by Israeli strikes on Saturday in the

latest exchange in the escalating conflict between the Middle

East rivals.

Israel said it was retaliating for Tehran's missile attack

on Israeli targets on Oct. 1.

Israel has been honing its air defences since coming under Iraqi

Scud salvoes in the 1991 Gulf war, in addition to receiving

support from the U.S. which said in October it had sent an

advanced anti-missile system to Israel to support those

defences.

Here are details of Israel's missile defences:

ARROW

The long-range Arrow-2 and Arrow-3 interceptors, developed

by Israel with an Iranian missile threat in mind, are designed

to engage threats both in and outside the atmosphere,

respectively. They operate at an altitude that allows for the

safe dispersal of any non-conventional warheads.

State-owned Israel Aerospace Industries is the

project's main contractor, while Boeing Co ( BA ) is involved in

producing the interceptors.

On Oct. 31, 2023, Israel's military said it had used the Arrow

aerial defence system for the first time since the outbreak

three weeks before of the war with Hamas to intercept a

surface-to-surface missile fired from the area of the Red Sea

towards its territory.

In September last year, Germany signed a letter of commitment

with Israel to buy the Arrow-3 system for nearly 4 billion euros

($4.2 billion).

DAVID'S SLING

The mid-range David's Sling system is designed to shoot down

ballistic missiles fired from 100 km to 200 km (62-124 miles)

away.

Developed and manufactured jointly by Israel's state-owned

Rafael Advanced Defense Systems and the U.S. RTX Corp,

formerly known as Raytheon, David's Sling is also designed to

intercept aircraft, drones and cruise missiles.

IRON DOME

The short-range Iron Dome air defence system was built to

intercept the kind of rockets fired by the Palestinian Islamist

movement Hamas in Gaza.

Developed by Rafael Advanced Defense Systems with U.S.

backing, it became operational in 2011. Each truck-towed unit

fires radar-guided missiles to blow up short-range threats like

rockets, mortars and drones in mid-air.

Rafael says it delivered two Iron Dome batteries to the U.S.

Army in 2020. Ukraine is seeking a supply as well in its war

with Russia, though Israel has so far only provided Kyiv with

humanitarian support and civil defences.

A naval version of the Iron Dome to protect ships and

sea-based assets was deployed in 2017.

The system determines whether a rocket is on course to hit a

populated area; if not, the rocket is ignored and allowed to

land harmlessly.

Iron Dome was originally billed as providing city-sized

coverage against rockets with ranges of between 4 and 70 km (2.5

to 43 miles), but experts say this has since been expanded.

LASER-BASED SYSTEM

Israel's interception systems cost between tens of thousands

and millions of dollars to shoot down incoming threats. Israel

is developing a laser-based system to neutralise enemy rockets

and drones at an estimated cost of just $2 per interception.

U.S. THAAD SYSTEM

The U.S. military said on Oct. 21 it had sent the advanced

anti-missile system THAAD, or the Terminal High Altitude Area

Defense system, to Israel.

THAAD is a critical part of the U.S. military's air defences

and is designed to intercept and destroy short-, medium-, and

intermediate-range ballistic missile threats in their terminal

phase of flight.

(Editing by William Maclean, Jan Harvey, Mike Stone, Andrew

Heavens, Daniel Wallis and Mark Heinrich)