The TRP Spyre Flat Mount Disc Brake Caliper is a dual sided mechanical where both pads actuate providing even and precise clamping force. This translates into even pad wear and, with the addition of a simple cable barrel adjuster, the pads can be adjusted easily and hassle free. No frustration at completely adjusting the whole caliper, only to have it continue to drag the fixed side, adding wear! All of this in an incredibly thin 40mm wide, 154g slender package that works with any of the drop bar levers on the market. TRP Spyre Flat Mount Disc Brake Caliper Features Dual sided actuation for even pad wear Simple adjustment and set up Works with ALL cable actuated road levers. Compressionless housing highly recommended. Ultra-grippy TRP semi-metallic pads Shimano M525/M515 are also compatible with Spyre calipers  Recommend using a 160mm rotor on the front Rotors and adapters sold separately