210J16 Poly-V rib belt. STANDARD DUTY. 16 Ribs. 21” (533mm) Length - 16-PJ533 Metric belt. Consumer Brand “J” Series Poly-V (Micro V) ribbed belts are designed to replace OEM belts on extra heavy-duty applications such as 210J16 power tool belts, compressor belts, 210J16 (16-Rib PJ533) fitness drive belts, and electric motor drive belts. AKA: J16-210 Belt.