Spare brass tubes for Seam Ripper & Crochet woodturning project kits from Penn State Industries; Use to replace damaged tubes, or to work ahead on your project (5) pre-scuffed tubes per pack; Each tube has an 8 millimeter outer diameter; Each tube is 3-1/8" long; Can be used interchangeably with PKSR2TU Compatible with Single Small Blade Seam Ripper Kits PKSR124, PKSR1, PKSR1SC; Compatible with Large & Small Blade Seam Ripper Kits PKSR224, PKSR2, PKSR2SC Compatible with 2-in-1 Seam Ripper & Pointed Tool Kits PKSR424, PKSR4CH, PKSR4SC, PKSR3; Compatible with Double Needle Threader Kits PKSRNT24 and PKSRNTCH Compatible with Crochet Hook Set Kit PKCROCHET, Handle PKCROHAN, and Crochet Hook Necklace Kit PKCRONEC Spare brass tubes for Seam Ripper & Crochet woodturning project kits from Penn State Industries; Use to replace damaged tubes, or to work ahead on your project. (5) pre-scuffed tubes per pack; Each tube has an 8 millimeter outer diameter; Each tube is 3-1/8" long; Can be used interchangeably with PKSR2TU. Compatible with Single Small Blade Seam Ripper Kits PKSR124, PKSR1, PKSR1SC; Compatible with Large & Small Blade Seam Ripper Kits PKSR224, PKSR2, PKSR2SC. Compatible with 2-in-1 Seam Ripper & Pointed Tool Kits PKSR424, PKSR4CH, PKSR4SC, PKSR3; Compatible with Double Needle Threader Kits PKSRNT24 and PKSRNTCH. Compatible with Crochet Hook Set Kit PKCROCHET, Handle PKCROHAN, and Crochet Hook Necklace Kit PKCRONEC.