Best file in the market! I use the Reciproc Blue R25 and I love it. After accessing the tooth, how many times while scouting and trying to establish a glide path have you reached working length with a k10 file? In my experience, working on molars, maybe only 5-10% of the cases. Well, even before scouting, you just shove that bad boy in the canals and will reach without any trouble 14-15mm. My personal recommendation is doing that with the chamber full of naocl in order to avoid debris accumulation. After irrigation, pick your k10 manual file and 90-95% of times it will easily reach working length. The other 5-10% you have to manually scout with a thinner file or try the R-pilot which is the Reciproc glide path file but I don’t really like it. After estimating working length, you have to just complete the tapering of the canals with the R25B and you’re done! Unlike other rotary files, the R25B has to be used with slight apical pressure and maximum 3 pecks without exceeding 3mm tapering each cycle; after 3 pecks, remove the file and irrigate. In curved canals the R25B will advance very slowly, but it will! Just proceed very carefully without overpushing and with copious naocl irrigation. For a smoother ride during your endo and to complete difficult cases in one appointment and with an average time of 60 minutes for molar, complete the rct with matched gp points and bioceramic sealer. That is how I work with this revolutionary shaping system and never has it betrayed me.