A premium U-brake from DiaTech. These have been around for awhile and are reasonable, reliable an have a great feel.
The brake starts as the DiaTech Hombre, then receives the "Fiesta" hop-up kit, usually in green.
The is The Building Edition with Red Fiesta hardware. The Building is the distributor for longtime allies S&M and Fit.
This caliper will generally fit any BMX Freestyle bike with U-brake mounts, so every Fit, Sunday and otherwise that has come from a legit BMX shop recently.