SMC磁性開關用來檢測氣缸活塞位置的，即檢測活塞的運動行程的。
SMC公司D系列磁性開關記號如下：
D-□中，□中無記號或為A、B、C、E、Z者為有觸點式，□中為F、G、H、J、K、M，P、Y者為無觸點式。
SMC有觸點磁性開關氣壓力克服彈簧力，推動由磁鐵的活塞運動到一定位置，舌簧開關接通。設定壓力調節靠調節螺釘改變彈簧預緊力來實現。工作原理：通過機械觸點的動作進行開關的通（ON）斷（OFF）的方式。
SMC無觸點磁性開關壓力感受部分使用硅擴散型半導體壓力傳感器。工作原理：利用半導體特性加上放大回路構成的開關形式。
SMC磁性開關現貨型號：
D-A33
D-A33A
D-A33C
D-A33C-8
D-A34
D-A34A
D-A34C
D-A34C-4
D-A44
D-A44A
D-A44C
D-A44C-4
D-A53L
D-A54L
D-A54L-588
D-A54Z
D-A56L
D-A59WL
D-A64L
D-A67L
D-A72HL
D-A72L
D-A73
D-A73C
D-A73CL
D-A73CN
D-A73CZ
D-A73EL
D-A73HL
D-A73HZ
D-A73L
D-A73Z
D-A76HL
D-A76HZ
D-A76L
D-A77L
D-A79WL
D-A80
D-A80CL
D-A80H
D-A80HL
D-A80L
D-A90L
D-A90L-588
D-A90VL
D-A90Z
D-A93
D-A93L
D-A93VL
D-A93VZ
D-A93Z
D-A93Z-588
D-A96
D-A96L
D-A96VL
D-B30J
D-B31
D-B31J
D-B35
D-B35J
D-B53
D-B53L
D-B53Z
D-B54L
D-B54Z
D-B59WL
D-B60L
D-B64L
D-B71L
D-B73-110
D-B73CL
D-B73CZ
D-B73L
D-B73P
D-B73PL
D-B73Z
D-B76L
D-B77C-72
D-B77P
D-B80L
D-C73
D-C73CL
D-C73CN
D-C73CZ
D-C73EL
D-C73L
D-C73Z
D-C76L
D-F59F
D-F59FL
D-F59L
D-F59W
D-F59WL
D-F5BAL
D-F5BAL-277
D-F5BASDPC
D-F5BAZ
D-F5DWL
D-F5NTL
D-F5PL
D-F5PWL
D-F5PWSAPC
D-F5PWZ
D-F6BL
D-F6NL
D-F6PL
D-F79F
D-F79FL
D-F79L
D-F79L-50
D-F79WL
D-F79WSDPC
D-F79Z
D-F7BAL
D-F7BAVL
D-F7BAVZ
D-F7BAZ
D-F7BVL
D-F7BVL-277
D-F7BVL-50
D-F7BVSAPC
D-F7BVZ
D-F7BWL
D-F7BWVL
D-F7BWVSDPC
D-F7DWSC
D-F7K
D-F7LFL
D-F7NJL
D-F7NJZ
D-F7NTL
D-F7NVL
D-F7NWL
D-F7NWVL
D-F7NWVSDPC
D-F7PL
D-F7PL-214
D-F7PMAPC
D-F7PSAPC
D-F7PSC
D-F7PVL
D-F7PW
D-F7PWL
D-F8BL
D-F8BL-61
D-F8BZ
D-F8N
D-F8N-61
D-F8NL
D-F8NMAPC
D-F8NZ
D-F8PL
D-F9BAL
D-F9BL
D-F9BL-277
D-F9BL-50
D-F9BL-61
D-F9BVL
D-F9BVL-50
D-F9BVZ
D-F9BW
D-F9BWL
D-F9BWSDPC
D-F9BWV
D-F9BWVL
D-F9BWVSDPC
D-F9BWZ
D-F9BZ
D-F9GL
D-F9HL
D-F9NL
D-F9NV
D-F9NVL
D-F9NWL
D-F9NWSDPC
D-F9NWVL
D-F9NWVSDPC
D-F9NZ
D-F9PL
D-F9PSAPC
D-F9PVL
D-F9PWL
D-F9PWVSBPC
D-F9PWZ
D-F9PZ
D-M9B
D-M9BAL
D-M9BASAPC
D-M9BASBPC
D-M9BASDPC
D-M9BAVL
D-M9BAZ
D-M9BL
D-M9BL-746
D-M9BM
D-M9BSAPC
D-M9BV
D-M9BVL
D-M9BVM
D-M9BVSAPC
D-M9BVZ
D-M9BWL
D-M9BWL-900
D-M9BWM
D-M9BWMAPC
D-M9BWSDPC
D-M9BWVL
D-M9BWVSDPC
D-M9BWVZ
D-M9BWZ
D-M9BZ
D-M9K
D-M9N
D-M9NAL
D-M9NASPC
D-M9NAVL
D-M9NL
D-M9NL-746
D-M9NM
D-M9NMAPC
D-M9NSAPC
D-M9N-SWY
D-M9NV
D-M9NVL
D-M9NVMAPC
D-M9NVZ
D-M9NWL
D-M9NWMAPC
D-M9NWVL
D-M9NWVZ
D-M9NWZ
D-M9NZ
D-M9P
D-M9P-382
D-M9PAL
D-M9PAVL
D-M9PL
D-M9PL-588
D-M9PL-746
D-M9PLAPC
D-M9PMAPC
D-M9PSAPC
D-M9PSDPC
D-M9PV
D-M9PVL
D-M9PVMAPC
D-M9PVSAPC
D-M9PVZ
D-M9PWL
D-M9PWSAPC
D-M9PWVL
D-M9PWVM
D-M9PWZ
D-M9PZ
