Replacement LW350 4 Watt lamp. Type F4T5/BL/350. UV peak at about 352 nm. Length 6 inches ~15 cm. The lamp can be used in these fixtures. UVP, LLC: UVL-4, UVL-21, H4-L, M-16, UVL-14, UVL-24, UVLS-24, UVLM-24, and 3UV-34. Raytech Industries: LS-7 and LW-4.