The plus in the OB-250+TP is the ultra-premium JLS #12 tone ring. Developed by master caster Jim Stull of San Antonio Texas this ring is the result of years of analyzing many pre-WW ll G-word tone rings to ascertain the formula of the bronze alloy used to make them the sought-after pieces of hardware they ve become. This long-skirt tone ring improves the contact between the neck the rim and the tone ring increasing the transmission of energy from the pot to the neck. It mimics the tone of the costly originals at a tiny fraction of the original s cost. The OB-250+TP Professional Bluegrass Banjo adds the phenomenal Tony Pass/Schaefer birch (recovered from the bottom of Lake Superior) block-style rim for even more powerful tone. The OB-250+TP includes a hardshell case.