I have a 671 and like other 671 owners who have bought this kit I found the side brushes did not fit. I did some research and took some photos of my Block 671. The first view is a top view of the brushes side by side. Focus on the holes, indentations, and the shape of the heads. Both heads fit into the notch present on the 671, the original fits snugly and the new one touches the tops of the polygon but is looser. The inner hole of the original is smaller and holds the screw tight. The inner hole of the new one is large and doesn't fit the screw exactly. The outer hole (recess) of the old one is much larger than the one in this kit. The second view is similar but better shows the depth of the holes. The third and fourth pictures show the original side brush and the included brush when the original screw is installed in these holes. The screw fits into the notch of the original screw head, but rests against the notch of the kit version. The kit does not include a screw so the kit version connects to the 671 screw socket and holds the brush in place. I could not find replacement side brushes with the same configuration as the original for the 671 that I purchased from Revain.
Dyson V8 Absolute: The Ultimate Cordless Vacuum for Effortless Cleaning
142 Review
Vacuum cleaner Deerma DX118C RU, white/grey
144 Review
iRobot Roomba 692: Smart Robot Vacuum with Wi-Fi, ๐ค Alexa Compatibility, and Pet-Friendly Features for Effortless Cleaning on Any Surface
138 Review
Xiaomi Mi Robot Vacuum-Mop Essential Robot Vacuum Cleaner, white
284 Review