7/16" Crown For use with Bostitch: PC1000, PC2000, PC4000, PC5000, H30-8 and P6C-8 staples. STCR50191/2-4M and STCR50191/2-1M do not fit H30-8 or P6C-8 staples. STCR50191/2-1M also fits PC3000.