used ladder mits for yrs till i saw a painter with sml pushchair wheels bolted to the top of the ladder, so i did the same its brill has the same grip as mits also lets u run ur ladders up the wall when extending them without marking walls paint etc, they even let you put ur ladder in the corner of windows with extra grip/ they are bolted through so that the wheels are on the inside of the ladder then u can retract ur ladder down as far as you like drill a 10mm hole through the top of each stile then put bolts through with nyloc nuts,mine are still goin after 5 yrs without a problem even on my triple aextension ladders which used to be a pain to extend,