I don't know if it is the one Monte mentioned, but the Whites has a variety of names for basically the same series of coils. The Blue Max 600 is basically the same as the Black Max 5.3 and the Bullseye 5.3. The Blue Max 800 is the same as the Royal 800. The Blue Max 950 is the same as the Black Max 950. Some of these coils are white, some are black and some are maroon. Some say Precision Scan and others just have logo and size. Just depends on when they were manufactured and which detector they were originally intended for. Regardless, the 6.59kHz coils will work on the XLT, 6000XL, XL PRO, ID series, IDX, IDX PRO, QXT, QXT PRO, CL III and the 5900. There may be more, but that is all I can think of right now. HH Randy