These are two texture overrides for the Maxis “Ladderlike” stairs: one for the specular that makes them less glossy (because .. high-gloss stairs? Hello?) and one that overrides the white option with a whitewood one. There are two separate packages, so you can use either or both.
How visible the glossiness is in game depends on the angle of light vs. viewing angle, hence the funky perspective on that screenshot. The specular override applies to all colour options.
Overrides the following:
0x00B2D882-0x00000000-0x9ECDE88ABE24F53F — specular texture
0x00B2D882-0x00000000-0xBACDA0480214ED39 — white(wood) texture