Assertion: shaver's design | /r/HasProperty | useful
Facets:
value: very
type: DEGREE
Source sentences:
text: This design was very useful, because the usual Soviet apartment of the 1960s had very few sockets, but somewhat unsafe; the brass cylinders of the secondary socket were uncovered at the ends (to allow them to be unscrewed easily), recessed by only 3 mm, and provided bad contact because they relied on the secondary plug's bisected expanding pins.