Boulderfly Nylon Tip Microstop & Countersink Kit All bronze bearings with 9/32" travel - Rated to 3000 RPM 0.001" increment depth adjustment - Positive Adjustment Lock 1/4" diameter chucking shank - 5/8" cutter capacity for 1/4-28 threaded bits Nylon threaded No-Mar foot piece #40, #30, #21, #10, and 1/4" 3-flute 100 countersinks - 1/2" body - 1/4-28 thread