This is a set of NBHM2 (slide head handle) and BA23 (socket adapter). ■ Model: NBHM2 ■ Manufacturer: NEPROS (Nepros/KTC) ■ Overall Length: 120mm ■ Weight: 42g ■ Model: BA23 ■ Manufacturer: KTC ■ Overall Length: 22mm ■ Socket Size (Female): 6.3mm ■ Socket Size (Male): 9.5mm ■ Weight: 16g The NBHM2 has a spherical head shape, making it more compact, and it moves to the end of the handle, so the tip is less likely to get in the way. Also, it has a stop position in the center, making it easier to work with. This is a used item that has been in someone's hands before. Please understand this before purchasing.