Poland delivers combat clothing as well, as I've seen numerous Ukrainian soldiers wearing a Polish body armour, even in the standard Polish camouflage.
On top of that, Poland does deliver some decommissioned anti-armour weapons.
en.wikipedia.org
It's not a super duper hyper über AT weapon, but the grenade is able to pierce 260mm of steel which is enough to fvck up a BTR, a BMD or a BMP from any angle. Unlike the modern weapons like the NLAW or the Javelin, its warhead is armed instantly, so it does not require any minimum distance to destroy the target. It's great to be used from inside buildings, while the RPG-7 requires a lot of empty space behind you to be fired. It's light and portable, so it's great to be used for ambushes and targeting vehicles from windows on upper floors.
Here, you can see a Ukrainian instructor training a group of soldiers: