Abstract: A snap-on, wire pay-off cap assembly to facilitate the unreeling of wire past one end of a wire filled spool, comprising a wheel adapted to be engaged by the wire being de-reeled, a circular brush disposed broadside to the wheel and having tines extending past the wheel periphery, a support member rotatably mounting the wheel and fixedly mounting the brush in their respective operative positions, and an operable clamp carried by the support member and adapted to engage the rim of one of the spool flanges for holding the cap assembly captive at one end of the spool. The clamp includes several radially extending arms which have hooks at their ends, to latch over the rim of the flange. Spring means associated with one of the arms biases it in a radially inward direction to thereby maintain the engagement of the hooks and the rim.