  The type II spicule has been speculated to provide enough hot plasma to play
an important role in the mass loading and heating of the corona. We analyse the
disc counterpart to type II spicules, RBEs, in three high quality datasets from
CRISP at the SST. In a quiet Sun region at disc centre we find lower Doppler
velocities, 15-40km/s, and Doppler widths, 2-15km/s, of RBEs than in earlier
coronal hole studies, 30-50km/s and 7-23km/s, respectively. We examine the
spatial dependence of Doppler velocities and widths along RBE axes and conclude
that there is no clear trend over the FOV or in individual RBEs in quiet Sun at
disc centre. These differences with previous coronal hole studies are
attributed to the more varying magnetic field configuration in quiet Sun
conditions. Using an extremely high cadence dataset allowed us to improve
greatly on the determination of lifetimes of RBEs, found to range from 5 to 60s
with an average of 30s, as well as the transverse motions in RBEs, with
transverse velocities up to 55km/s and averaging 12km/s. Furthermore, our
measurements of the recurrence rates of RBEs provide important new constraints
on coronal heating by spicules. We also see many examples of a sinusoidal wave
pattern in the transverse motion with periods averaging 54s and amplitudes from
21.5 to 129km, agreeing well with previous studies of wave motion in limb
spicules. We interpret the appearance of RBEs over their full length within a
few seconds as the result of a combination of three kinds of motions as
reported earlier for spicules. Finally, we look at the temporal connection
between Ha and Ca 8542 RBEs and find Ca 8542 in addition to being located
closer to the footpoint also appear before the Ha RBE. This connection supports
the idea that heating occurs in spicules and contribute more weight to the
prominence of spicules as a source for heating and mass loading of the corona.
