You get 3 plungers

Each pump uses 3 plungers

3-pack 51040009 15x9x25 15mm General Pump , Interpump i6 Replacement Plunger

Series 51

For

General Pump

T1508, TT551, TT561, TT741, TT751, TT901, TT931, TT941, TT951, TT1508, 

TT1510, TT1511, TT1512, TT1513, TT9061, TT9071, TT9091 , TT2028 , TT2035E

TT2035G

For 

Interpump Pump  : W1507, WW55, WW56 , WW74, WW75, WW90, WW93, WW94, 

WW95, WW906, WW907, WW909, WW1508, WW1509, WW1510, WW1511, WW1513

For Turbo and Boxjet Models

15 , 19 , 21 , 8-70 , 8-90

10-100 , 11-50 , 11-70 , 11-120

13-90

For Big Bang and Formula 99 Models

F-122 , F-124 , X-117S , X-161

X-220S , X-230 , X-240S

Ceramic Plungers General Pump , Interpump i6 Replacement

Plunger Specs: 15mm x 9mm x 25mm

Each pump uses 3 plungers

Replace as needed