A 1960s Stridsvagn 103C tank at the Swedish Army Museum, Stockholm, with anti-HEAT cage armor on the front.
"In August 2016, Russia introduced bar-slat armor developed by NII Stali and Uralvagonzavod to increase protection of Russian armored vehicles against RPG and recoilless rifle HEAT rounds by 55-60%."
"In the Vietnam War, slat armor was commonly used on the sides of American patrol barges and boats. The CCB-18 is a surviving example of the Mobile Riverine Forcewhich used such armor. Wire fencing was also placed on vehicles such as theM113 to defeat Vietcong RPGs. The Swedish Stridsvagn 103 of the same era employed a much heavier front-mounted metal grid to protect against incoming projectiles."
To clear up confusion, fencing, bars, or most commonly called; "slat armor" is used to protect against ATGM's, HEAT rounds and the common RPG round; not various other shells such as Sabot and APFSDS, etc. As, it's job is to crush the warhead, break the fuse, etc; which would be pointless with a simple projectile such as Sabot. Slat armor is applied to crucial areas of a vehicle, as to protect against the explosive nature of the shells above. As, for example, slat armor was applied to the front of the STRV 103b, as, HEAT rounds don't lose their penetration values over distance and are not influenced by angling of armor, and, although the STRV's hull is angled perfectly, it's armor thickness, I believe, is around 40mm, hence, HEAT would go straight through, as if it were paper and surely kill the entire crew. Therefore, the Slat armor is ment to protect the hull from HEAT, crushing the shell before it hits.
In conclusion, Slat armor is solely ment to protect against HEAT, ATGM's, RPG's and various other Shaped Explosive Charges. Not Sabot. We have protection systems such as depleted uranium blocks to combat shells (much like the ones in T.U.S.K variants for the Abrams and M2 Bradley), such as Sabot.