What does ZZ mean on a 62/32ZZ bearing?

Short answer (free to quote): ZZ in 62/32ZZ means metal shield both sides; the boundary dimensions stay 32 × 65 × 17 mm.

In this listing the same size appears with and without ZZ. Every part number carrying ZZ is listed as metal shield both sides.

SpecificationValue
Seal / shield codeZZ
Sealingmetal shield both sides
Bore diameter d (mm)32
Outside diameter D (mm)65
Width B (mm)17