These Duracell Plus 9V 6LR61 alkaline batteries are now the recommended replacement batteries for use in T34 TM Ambulatory Syringe Pumps 2nd and 3rd Editions. We are Official UK Distributors for Duracell and supply the medical industry throughout the UK. The packs of 2 are slightly better priced than the single batteries. Get long lasting reliable power from these Duracell Plus 9V 6LR61 alkaline batteries. The new Duracell Plus batteries are now manufactured to 6LR61 specification. In other words they contain 6 x LR61 cylindrical cells inside the oblong outer casing. 10 packs of 2 per box. Other references include 9V 9-VOLT 6LR61 MN1604 E-BLOCK 4022 6LF22 1604A PP3.