Bosch Gcm12 vs Bosch Ros20: specs compared
Updated 05 September 2026.
35 mm
Bosch Ros20 wins on mating diameter
On mating diameter, Bosch Ros20 leads: 35 mm versus 32 mm.
| Spec | Bosch Gcm12 | Bosch Ros20 |
|---|---|---|
| Port type | female socket (hose goes into it) | male spigot (hose goes over it) |
| Inner diameter (ID) | 1-1/4 in, 32 mm | |
| Manufacturer designation | rear approx 1-1/4 in ID (32 mm) | 35 mm OD (EU convention) |
| Mating diameter (mm) | 32 | 35 |
| Outer diameter (OD) | 1-3/8 in, 35 mm |
Questions and answers
Which has the higher mating diameter, Bosch Gcm12 or Bosch Ros20?
On mating diameter, Bosch Ros20 leads: 35 mm versus 32 mm.
How do Bosch Gcm12 and Bosch Ros20 compare?
On mating diameter, Bosch Ros20 leads: 35 mm versus 32 mm.