Genuine Bosch 1610210121 — O‑ring / sealing ring for rotary hammers. Precision moulded from nitrile rubber (NBR) to resist oil, dust and repeated compression; typically supplied in green and used as the sealing/compression ring inside the tool’s hammer/gear assembly.

Key specifications: internal diameter 17 mm × cross‑section 3 mm (outer diameter ≈ 23 mm). Fits as the replacement O‑ring specified by Bosch for several SDS‑plus rotary hammer models.

Example models this part is listed for: Bosch GBH 2‑28 (including GBH 2‑28 F / D variants), GBH 3‑28 (DFR series) and series like the GBH 36 V‑LI. Use this part when worn seals are causing loss of hammering performance, dust ingress or oil/air leaks in those tools.

What you get: one original Bosch 1610210121 O‑ring made to Bosch tolerances for direct fit and reliable sealing — a small, low‑cost part that restores proper sealing and helps avoid further internal damage.

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