The Red Mason Bee (Osmia bicornis) is about the same body size as the European Honeybee (Apis mellifera).
Females are larger than males.
Males have gray-white hairs on their faces while females have black facial hair.
In addition, males have long antenna while females have short antenna.
These bees are not aggressive.
All photos here show a male; the bee on the last photo is much more black than the ones on the other photos.

Landgoed Oostbroek, De Bilt, The Netherlands, 11 April 2019