Nihon Kohden SpO2 sensor. (short) Compatible with: BSM-2300 Life Scope I, BSM-2301, MSM 2301K, 2303 Life Scope I, 2303K, BSM 2350 Life Scope L, BSM-2351, 2353 Life Scope L, BSM-4100 Life Scope P, BSM 4101, 4103 TL-101T, 4111, 4113 Life Scope P, BSM-5100 Life Scope A, BSM-5105, 5135 Life Scope A, Life Scope TR, BSM-6000 series, BSM-6301K, BSM-6501K, BSM-6701K , BSM-9510 Life Scope M, BSM-9800 Life Scope S, Oxipal P225F.