Our sealed foam swabs feature 100 PPI polyurethane foam heads for strength and abrasion resistance. They have excellent particle entrapment and retention, and are therefore ideal for applying and removing excess materials. They are compatible with Isopropyl Alcohol. Their sealed polyurethane foam heads are oval-shaped and measure 0.5â€ diameter x 0.75â€ in length (1.3 x 1.9 cm); the polypropylene handle is 6â€ (0.3 x 16 cm) long. Packages of 100 swabs.